Pulmonary Hypertension Drugs

Overview

Pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension ( PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance)

Pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension ( PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance) is defined as an elevated pulmonary arterial pressure. 

• Elevated pulmonary arterial pressure consistent with PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance: ≥ 20 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma Hg at rest
• Normal pulmonary arterial pressure: 8–20 mmHg
• WHO classifications:
  • Group 1: pulmonary arterial hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension ( PAH PAH The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity. Glomerular Filtration)
  • Group 2: PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance due to left heart disease
  • Group 3: PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance due to lung disease and/or hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage
  • Group 4: PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance due to pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy obstructions
  • Group 5: PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance with unclear and/or multifactorial mechanisms

General therapeutic options

• Long-term oxygen:
  • Aim to maintain oxygen saturations＞92%
  • Helps slow down progression 
• Long-term anticoagulation:
  • If condition is due to chronic pulmonary embolism Pulmonary Embolism Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. The causative factors include thrombi, air, amniotic fluid, and fat. In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. Pulmonary Embolism (PE)
  • Helps prevent progression in other causes
• Pharmacotherapy (which generally acts via vascular smooth muscle relaxation → vasodilation → drop in pulmonary arterial pressure):
  • Nitric oxide– cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors enhancers (soluble guanylate cyclase Guanylate cyclase An enzyme that catalyzes the conversion of GTP to 3. Diarrheagenic E. coli (sGC) stimulant, phosphodiesterase type 5 (PDE-5) inhibitors)
  • Prostacyclin Prostacyclin A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors agonists 
  • Endothelin receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors antagonists 
  • Calcium channel blockers Calcium Channel Blockers Calcium channel blockers (CCBs) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBs: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) ( CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers))
• Surgery:
  • Thromboembolectomy for chronic thromboembolic disease
  • Very effective
• Severe PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance has a very poor survival (＜5 years).

Phosphodiesterase-5 (PDE-5) Inhibitors

Chemistry

• Mimics the purine ring of cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors 
• Medications:
  • Sildenafil Sildenafil A phosphodiesterase type-5 inhibitor; vasodilator agent and urological agent that is used in the treatment of erectile dysfunction and primary pulmonary hypertension. Phosphodiesterase Inhibitors
  • Tadalafil Tadalafil A carboline derivative and phosphodiesterase 5 inhibitor that is used primarily to treat erectile dysfunction; benign prostatic hyperplasia and primary pulmonary hypertension. Phosphodiesterase Inhibitors

Mechanism of action

• PDE-5 is an enzyme that regulates smooth muscle tone Muscle tone The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. Skeletal Muscle Contraction in blood vessels by degrading cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors.
• PDE-5 inhibitors are both competitive and selective inhibitors of PDE-5 causing:
  • ↓ Hydrolysis Hydrolysis The process of cleaving a chemical compound by the addition of a molecule of water. Proteins and Peptides of cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors
  • ↑ Intracellular cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors → ↓ calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes + antiproliferative + anticoagulant effect
  • Resultant effects: relaxation of blood vessels → ↑ pulmonary blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure → ↓ pulmonary arterial pressure

Pharmacokinetics Pharmacokinetics Pharmacokinetics is the science that analyzes how the human body interacts with a drug. Pharmacokinetics examines how the drug is absorbed, distributed, metabolized, and excreted by the body. Pharmacokinetics and Pharmacodynamics

• Absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption: 
  • Rapid oral absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption 
  • Should be taken on an empty stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy
  • Fatty meals can delay absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption.
• Distribution:
  • Peaks in 1 hour 
  • Highly protein bound
• Metabolism:
  • Tadalafil Tadalafil A carboline derivative and phosphodiesterase 5 inhibitor that is used primarily to treat erectile dysfunction; benign prostatic hyperplasia and primary pulmonary hypertension. Phosphodiesterase Inhibitors with longer half-life Half-Life The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity. Pharmacokinetics and Pharmacodynamics than sildenafil Sildenafil A phosphodiesterase type-5 inhibitor; vasodilator agent and urological agent that is used in the treatment of erectile dysfunction and primary pulmonary hypertension. Phosphodiesterase Inhibitors
  • Hepatic metabolism via cytochrome P450 Cytochrome P450 A superfamily of hundreds of closely related hemeproteins found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (mixed function oxygenases). In animals, these p450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (biotransformation). They are classified, according to their sequence similarities rather than functions, into cyp gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the cyp1, cyp2, and cyp3 gene families are responsible for most drug metabolism. Drug-induced Liver Injury system (CYP3A)
  • Active metabolites
• Excretion: Feces primarily

Indications

• PAH PAH The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity. Glomerular Filtration (WHO group 1)
• Other indications:
  • Erectile dysfunction Erectile Dysfunction Erectile dysfunction (ED) is defined as the inability to achieve or maintain a penile erection, resulting in difficulty to perform penetrative sexual intercourse. Local penile factors and systemic diseases, including diabetes, cardiac disease, and neurological disorders, can cause ED. Erectile Dysfunction (ED)
  • Benign Benign Fibroadenoma prostatic hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation ( BPH BPH Benign prostatic hyperplasia (bph) is a condition indicating an increase in the number of stromal and epithelial cells within the prostate gland (transition zone). Benign prostatic hyperplasia is common in men > 50 years of age and may greatly affect their quality of life. Benign Prostatic Hyperplasia)

Adverse drug effects

• CNS:
  • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
  • Paresthesia
  • Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
  • Insomnia Insomnia Insomnia is a sleep disorder characterized by difficulty in the initiation, maintenance, and consolidation of sleep, leading to impairment of function. Patients may exhibit symptoms such as difficulty falling asleep, disrupted sleep, trouble going back to sleep, early awakenings, and feeling tired upon waking. Insomnia
  • Visual disturbances ( sildenafil Sildenafil A phosphodiesterase type-5 inhibitor; vasodilator agent and urological agent that is used in the treatment of erectile dysfunction and primary pulmonary hypertension. Phosphodiesterase Inhibitors: blue-tinted vision Blue-Tinted Vision Phosphodiesterase Inhibitors)
• Respiratory:
  • Epistaxis Epistaxis Bleeding from the nose. Granulomatosis with Polyangiitis
  • Rhinitis Rhinitis Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis
• Cardiovascular: 
  • Flushing
  • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
  • Syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope
  • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
• GI: 
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics
  • Dyspepsia Dyspepsia Impaired digestion, especially after eating. Lactose Intolerance
• Musculoskeletal: 
  • Myalgia Myalgia Painful sensation in the muscles. Ion Channel Myopathy
  • Back pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Genitourinary: priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions

Precautions

• Caution with individuals who may be predisposed to priapism Priapism A prolonged painful erection that may lasts hours and is not associated with sexual activity. It is seen in patients with sickle cell anemia, advanced malignancy, spinal trauma; and certain drug treatments. Penile Anomalies and Conditions:
  • Sickle cell anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types
  • Multiple myeloma Multiple myeloma Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma ( MM MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma)
  • Leukemia
• Caution in those with: 
  • History of bleeding 
  • Cardiovascular diseases
  • Hepatic and renal impairment

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Hypersensitivity to PDE-5 inhibitors or any drug component
• Concurrent use of nitrates Nitrates Nitrates are a class of medications that cause systemic vasodilation (veins > arteries) by smooth muscle relaxation. Nitrates are primarily indicated for the treatment of angina, where preferential venodilation causes pooling of blood, decreased preload, and ultimately decreased myocardial O2 demand. Nitrates (e.g., nitroglycerin Nitroglycerin A volatile vasodilator which relieves angina pectoris by stimulating guanylate cyclase and lowering cytosolic calcium. It is also sometimes used for tocolysis and explosives. Nitrates) 
• Use with riociguat, a guanylate stimulator (↑ hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension)
• Use with protease inhibitors Protease Inhibitors Compounds which inhibit or antagonize biosynthesis or actions of proteases (endopeptidases). Anti-HIV Drugs (↑ concentration of PDE-5 inhibitors)
• Prior episode of non-arteritic anterior ischemic optic neuropathy Neuropathy Leprosy (NAION)

Drug interactions

• An increased risk of hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension is associated with:
  • Ethyl alcohol
  • Alpha-1 blockers
  • Nitroprusside Nitroprusside A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins. Nitrates
  • Blood pressure–lowering drugs
  • See other medications in contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inducers: ↑ concentration of PDE-5 inhibitors
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inhibitors: ↓ concentration of PDE-5 inhibitors
• Grapefruit juice: ↑ concentration of PDE-5 inhibitors

Soluble Guanylate Cyclase (sGC) Stimulator (Riociguat)

Chemistry

• 1st drug of the class 
• Direct stimulator of sGC

Mechanism of action

• sGC:
  • The intracellular mediator for nitric oxide
  • Located in smooth muscle component of vessel wall
• Riociguat directly stimulates sGC, leading to:
  • ↑ Biosynthesis Biosynthesis The biosynthesis of peptides and proteins on ribosomes, directed by messenger RNA, via transfer RNA that is charged with standard proteinogenic amino acids. Virology of cGMP cGMP Guanosine cyclic 3. Phosphodiesterase Inhibitors
  • ↓ Intracellular calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes → changes actin-myosin contractility → vasodilation
• Riociguat acts independently of NO.

Pharmacokinetics Pharmacokinetics Pharmacokinetics is the science that analyzes how the human body interacts with a drug. Pharmacokinetics examines how the drug is absorbed, distributed, metabolized, and excreted by the body. Pharmacokinetics and Pharmacodynamics

• Absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption: 
  • Good oral absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption 
• Distribution: 
  • Bioavailability Bioavailability Pharmacokinetics and Pharmacodynamics: 94%
  • Half-life Half-Life The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity. Pharmacokinetics and Pharmacodynamics: 12 hours 
  • Protein binding: 95%
• Metabolism: 
  • Hepatic cytochrome P450 Cytochrome P450 A superfamily of hundreds of closely related hemeproteins found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (mixed function oxygenases). In animals, these p450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (biotransformation). They are classified, according to their sequence similarities rather than functions, into cyp gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the cyp1, cyp2, and cyp3 gene families are responsible for most drug metabolism. Drug-induced Liver Injury enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes 
• Excretion: 
  • Feces and urine Urine Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the urethra. Bowen Disease and Erythroplasia of Queyrat

Indications

• Chronic thromboembolic pulmonary hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension (CTEPH)
• PAH PAH The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity. Glomerular Filtration (WHO group 1)

Adverse drug effects

• Embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week fetal toxicity Toxicity Dosage Calculation 
• Cardiovascular:
  • Palpitations Palpitations Ebstein’s Anomaly
  • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension 
• CNS:
  • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
  • Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
• GI:
  • Dyspepsia Dyspepsia Impaired digestion, especially after eating. Lactose Intolerance 
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics 
  • Vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
  • Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea 
  • Abdominal distension 
• ENT:
  • Nasal congestion 
  • Hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis
  • Epistaxis Epistaxis Bleeding from the nose. Granulomatosis with Polyangiitis
• Bleeding

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Hypersensitivity to riociguat or any of its components
• Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care
• Concurrent administration with NO donors (e.g., amyl nitrite Amyl nitrite A vasodilator that is administered by inhalation. It is also used recreationally due to its supposed ability to induce euphoria and act as an aphrodisiac. Nitrates)
• Use with PDE-5 inhibitors

Drug interactions

• ↑ Risk of hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension with other antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inducers: ↑ concentration of PDE-5 inhibitors
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inhibitors: ↓ concentration of PDE-5 inhibitors
• Antacids ↓ concentration of riociguat
• Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases ↓ plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products concentration by 50% 

Prostacyclin Receptor Analogues

Chemistry

• Synthetic prostacyclin Prostacyclin A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids analogues 
• Medications:
  • Epoprostenol Epoprostenol A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Hemostasis 
  • Treprostinil 
  • Iloprost 
  • Selexipag 

Mechanism of action

• Prostacyclin Prostacyclin A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids binds to the prostaglandin I2 ( PGI2 PGI2 A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids) receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors (called IP) in the plasma membrane Plasma membrane A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules. The Cell: Cell Membrane of pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy SMCs.
• Involves the cAMP-dependent pathway:
  • Triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) adenylate cyclase (AC) to convert ATP to cAMP cAMP An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth. Phosphodiesterase Inhibitors
  • cAMP cAMP An adenine nucleotide containing one phosphate group which is esterified to both the 3′- and 5′-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and acth. Phosphodiesterase Inhibitors activates protein kinase A Protein kinase A A group of enzymes that are dependent on cyclic amp and catalyze the phosphorylation of serine or threonine residues on proteins. Included under this category are two cyclic-amp-dependent protein kinase subtypes, each of which is defined by its subunit composition. Glycogen Metabolism (PKA), leading to processes that:
    • ↓ Calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes by activating potassium Potassium An element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Hyperkalemia channels Channels The Cell: Cell Membrane (membrane hyperpolarization Hyperpolarization Membrane Potential and repolarization Repolarization Membrane Potential)
    • Inhibits myosin Myosin A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind actins and hydrolyze mgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and mgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain. Skeletal Muscle Contraction light-chain kinase → smooth muscle relaxation → vasodilation 
    • Also exerts antiproliferative effect
• Selexipag differs from the other prostacyclin Prostacyclin A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids analogues, as it acts as a selective IP receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors agonist.

Comparison of prostacyclin Prostacyclin A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Eicosanoids analogues

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Hypersensitivity to the drug or its components
• Drug-specific contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
  • Epoprostenol Epoprostenol A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Hemostasis:
    • Chronic use in those with heart failure Heart Failure A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction. Total Anomalous Pulmonary Venous Return (TAPVR) due to severe left ventricular dysfunction
    • In those who developed pulmonary edema Pulmonary edema Pulmonary edema is a condition caused by excess fluid within the lung parenchyma and alveoli as a consequence of a disease process. Based on etiology, pulmonary edema is classified as cardiogenic or noncardiogenic. Patients may present with progressive dyspnea, orthopnea, cough, or respiratory failure. Pulmonary Edema during initiation
  • Treprostinil: The oral form is contraindicated in severe hepatic impairment.
  • Selexipag: Use of strong CYP2C8 CYP2C8 A liver microsomal cytochrome p450 hydroxylase that oxidizes a broad spectrum of substrates including steroids, fatty acids, and xenobiotics. Examples of pharmaceutical substrates for cyp2c8 include; paclitaxol; torsemide; and; amodiaquine. Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inhibitors with selexipag is contraindicated.

Drug interactions

• Epoprostenol Epoprostenol A prostaglandin that is a powerful vasodilator and inhibits platelet aggregation. It is biosynthesized enzymatically from prostaglandin endoperoxides in human vascular tissue. The sodium salt has been also used to treat primary pulmonary hypertension. Hemostasis, treprostinil, and iloprost enhance the action of medications with antiplatelet properties. 
• Antihypertensives Antihypertensives The 1st-line medication classes for hypertension include thiazide-like diuretics, angiotensin-converting enzyme inhibitors (ACEis), angiotensin II receptor blockers (ARBs), and calcium channel blockers (CCBS). Contraindications, adverse effects, and drug-to-drug interactions are agent specific. Hypertension Drugs may potentiate and ↓ blood pressure

Endothelin Receptor Antagonists

Chemistry

• Pyrimidine derivatives
• Medications:
  • Bosentan 
  • Macitentan 
  • Ambrisentan

Mechanism of action

• Competitive antagonist of endothelin receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors (endothelin receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors A (ET-A) and endothelin receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors B (ET-B)) on:
  • Endothelium Endothelium A layer of epithelium that lines the heart, blood vessels (vascular endothelium), lymph vessels (lymphatic endothelium), and the serous cavities of the body. Arteries: Histology
  • Vascular smooth muscle 
• Causes vasodilation and smooth muscle relaxation 
• Ambrisentan is a selective ET-A receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors antagonist, which is in contrast with bosentan and macitentan which are antagonists of both receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors.

Comparison of endothelin receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors antagonists

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Hypersensitivity to the drug or its components
• Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care ( embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week fetal toxicity Toxicity Dosage Calculation)
• Breastfeeding Breastfeeding Breastfeeding is often the primary source of nutrition for the newborn. During pregnancy, hormonal stimulation causes the number and size of mammary glands in the breast to significantly increase. After delivery, prolactin stimulates milk production, while oxytocin stimulates milk expulsion through the lactiferous ducts, where it is sucked out through the nipple by the infant. Breastfeeding 
• Severe liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease 
• Drug-specific:
  • Ambrisentan: contraindicated in idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis Idiopathic pulmonary fibrosis is a specific entity of the major idiopathic interstitial pneumonia classification of interstitial lung diseases. As implied by the name, the exact causes are poorly understood. Patients often present in the moderate to advanced stage with progressive dyspnea and nonproductive cough. Pulmonary Fibrosis (IPF)
  • Bosentan: 
    • Use with cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants (↑ bosentan levels)
    • Use with glyburide (which ↑ hepatotoxic effects)

Drug interactions

• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inhibitors: ↑ drug concentrations
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inducers: ↓ drug concentrations
• Cyclosporine Cyclosporine A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. Immunosuppressants: may ↑ ambrisentan concentration

Calcium Channel Blockers (CCBs)

Chemistry

• L-type CCB
• Medications:
  • Nifedipine Nifedipine A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers)
  • Amlodipine Amlodipine A long-acting dihydropyridine calcium channel blocker. It is effective in the treatment of angina pectoris and hypertension. Hypertension Drugs
  • Diltiazem Diltiazem A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of calcium ion on membrane functions. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers)
  • Verapamil

Classes of CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers)

• Dihydropyridines: 
  • Binds more selectively to vascular smooth muscle calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes channels Channels The Cell: Cell Membrane (vasodilator)
  • Can lead to reflex tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
  • Example: amlodipine Amlodipine A long-acting dihydropyridine calcium channel blocker. It is effective in the treatment of angina pectoris and hypertension. Hypertension Drugs
• Non-dihydropyridine:
  • Affects the heart contractility and conduction; less effect on vasodilation
  • Does not lead to reflex tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
  • Benzothiazepine:
    • Mainly acts on the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy (myocardial depressant) 
    • Acts as a cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) depressant and a vasodilator
    • Example: diltiazem Diltiazem A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of calcium ion on membrane functions. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) 
  • Phenylalkylamine:
    • Acts on cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) myocytes Myocytes Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal, cardiac, and smooth. They are derived from embryonic (precursor) muscle cells called myoblasts. Muscle Tissue: Histology (strong myocardial depressant)
    • Example: verapamil

Mechanism of action

• CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) bind BIND Hyperbilirubinemia of the Newborn the L-type calcium channels L-type calcium channels An optical isomer of quinine, extracted from the bark of the chinchona tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular action potentials, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) in cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) myocytes Myocytes Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal, cardiac, and smooth. They are derived from embryonic (precursor) muscle cells called myoblasts. Muscle Tissue: Histology, cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) nodal tissues, and VSCMs, leading to:
  • Closed L-type channels Channels The Cell: Cell Membrane
  • ↓ Calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes entry
• Smooth muscle relaxation → systemic vasodilation
• ↓ Cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) afterload Afterload Afterload is the resistance in the aorta that prevents blood from leaving the heart. Afterload represents the pressure the LV needs to overcome to eject blood into the aorta. Cardiac Mechanics leads to ↓ blood pressure (effective in hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension) 
• ↓ Myocardial contractility ( negative inotropic effect Negative Inotropic Effect Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers))
• ↓ Atrioventricular node Atrioventricular node A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart. Heart: Anatomy ( AVN Avn Hip Fractures) conduction velocity ( negative dromotropic effect Negative Dromotropic Effect Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers))
• ↓ Automaticity ( negative chronotropic effect Negative Chronotropic Effect Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers))
• ↓ Peripheral vascular resistance Vascular Resistance The force that opposes the flow of blood through a vascular bed. It is equal to the difference in blood pressure across the vascular bed divided by the cardiac output. Vascular Resistance, Flow, and Mean Arterial Pressure

Pharmacokinetics Pharmacokinetics Pharmacokinetics is the science that analyzes how the human body interacts with a drug. Pharmacokinetics examines how the drug is absorbed, distributed, metabolized, and excreted by the body. Pharmacokinetics and Pharmacodynamics

• Dosage Dosage Dosage Calculation forms: oral, intravenous
• Distribution: protein binding: 80%
• Metabolism: hepatic 1st-pass metabolism, primarily by CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers)
• Excretion: renal and feces

Indications

• PH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance:
  • Select cases of PAH PAH The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity. Glomerular Filtration (WHO group 1) undergo acute vasoreactivity testing to determine the likelihood of a response to CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers).
  • In those who test positive, proceed with CCB therapy.
  • In those who test negative, avoid CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) ( hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension, death).
• Other indications:
  • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
  • Stable angina Stable angina Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of myocardial ischemia. Stable and Unstable Angina
  • Coronary vasospasm Coronary vasospasm Spasm of the large- or medium-sized coronary arteries. Vasospastic Angina
  • Raynaud’s phenomenon
  • Supraventricular tachyarrhythmias
  • Migraine Migraine Migraine headache is a primary headache disorder and is among the most prevalent disorders in the world. Migraine is characterized by episodic, moderate to severe headaches that may be associated with increased sensitivity to light and sound, as well as nausea and/or vomiting. Migraine Headache and cluster headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess prophylaxis Prophylaxis Cephalosporins
  • Esophageal hyperperistalsis

Adverse effects

• Dihydropyridines:
  • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess (cerebral vasodilation)
  • Reflex tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children (especially with short-acting nifedipine Nifedipine A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers))
  • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
  • Flushing
  • Peripheral edema Peripheral edema Peripheral edema is the swelling of the lower extremities, namely, legs, feet, and ankles. Edema (dose-dependent; usually with amlodipine Amlodipine A long-acting dihydropyridine calcium channel blocker. It is effective in the treatment of angina pectoris and hypertension. Hypertension Drugs)
  • Gingival hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation
• Non-dihydropyridines:
  • Constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation (dose-dependent)
  • Fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
  • Bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias
  • AVN Avn Hip Fractures block
  • Worsening of cardiac Cardiac Total Anomalous Pulmonary Venous Return (TAPVR) output
  • Gingival hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation

Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation

• Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
• Hypersensitivity to CCBs CCBs Calcium channel blockers (CCBS) are a class of medications that inhibit voltage-dependent L-type calcium channels of cardiac and vascular smooth muscle cells. The inhibition of these channels produces vasodilation and myocardial depression. There are 2 major classes of CCBS: dihydropyridines and non-dihydropyridines. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers)
• Acute coronary syndrome:
  • Avoid nifedipine Nifedipine A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure. Class 4 Antiarrhythmic Drugs (Calcium Channel Blockers) or short-acting dihydropyridines. 
  • Short-acting dihydropyridines cause reflex tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children and worsen myocardial ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage.
• Use caution in liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease.

Drug interactions

• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inhibitors: ↑ drug concentrations
• CYP3A4 CYP3A4 Class 3 Antiarrhythmic Drugs (Potassium Channel Blockers) inducers (e.g., rifampin Rifampin A semisynthetic antibiotic produced from streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits dna-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms. Epiglottitis, carbamazepine Carbamazepine A dibenzazepine that acts as a sodium channel blocker. It is used as an anticonvulsant for the treatment of grand mal and psychomotor or focal seizures. It may also be used in the management of bipolar disorder, and has analgesic properties. First-Generation Anticonvulsant Drugs): ↓ drug concentrations