Cholinomimetic Drugs

Cholinomimetic drugs, also known as parasympathomimetics or cholinergic agonists, increase acetylcholine (ACh), which acts on cholinergic muscarinic and nicotinic receptors. Other cholinomimetic drugs result in a net cholinergic effect by inhibiting the cholinesterase enzyme. Muscarinic receptors are found in the CNS and are part of the parasympathetic nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system. General Structure of the Nervous System, which responds to cholinomimetics. Nicotinic receptors are found in the CNS at the neuromuscular junction. Physiologic effects on muscarinic receptors include bronchoconstriction, lacrimation, and bradycardia. Physiologic effects on nicotinic receptors include vasoconstriction, tachycardia, and elevated blood pressure. Cholinergic activation of muscarinic receptors on vascular endothelial cells cause an increase in nitric oxide, which diffuses to the adjacent vascular smooth muscle cells, resulting in smooth muscle relaxation/vasodilation and a paradoxical effect of the cholinomimetics on bronchial smooth muscle (constriction) and vascular smooth muscle (relaxation). Clinical uses of cholinomimetic agents include treatment of dementia, glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma, and as an aid for smoking cessation. The primary adverse effect of cholinergic drugs is overstimulation of the parasympathetic nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system. General Structure of the Nervous System. Symptoms result from excessive levels of ACh in synapses, glands, smooth muscles, and motor endplates.

Last update:

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Table of Contents

Share this concept:

Share on facebook
Share on twitter
Share on linkedin
Share on reddit
Share on email
Share on whatsapp

Chemistry and Pharmacodynamics

Acetylcholine (ACh) is a prototype direct-acting cholinergic drug. Cholinomimetics are direct activators of both the muscarinic and nicotinic cholinergic receptors.

Overview

  • A neurotransmitter at various synapses, nerves, and motor endplates in muscles:
    • Nerve impulse → ACh stored in the vesicles is released into the synaptic cleft → binds to a postsynaptic receptor → depolarization
    • ACh is degraded by the acetylcholinesterase (AChE) enzyme (present at tissue receptor sites and on RBCs)
  • ACh is released from sympathetic and parasympathetic neuronal terminals on:
    • Lacrimal glands 
    • Salivary glands Salivary glands The salivary glands are exocrine glands positioned in and around the oral cavity. These glands are responsible for secreting saliva into the mouth, which aids in digestion. There are 3 major paired salivary glands: the sublingual, submandibular, and parotid glands. Salivary Glands
    • Sweat glands
  • Overall effects are “wet”: tearing, sweating, and salivation

Mechanism of action and physiologic effects

  • Muscarinic cholinergic receptors: 
    • All 5 types (M1, M2, M3, M4, and M5) are G protein-coupled receptors → increased intracellular levels of calcium, which lead to:
      • Glandular secretion at exocrine glands
      • Vascular smooth muscle relaxation
      • ↓ Heart rate and contractility
  • Muscarinic receptor locations → effects:
    • Autonomic ganglia and exocrine glands: ↑ salivary/gastric acid secretion and diaphoresis
    • Blood vessel endothelium: M3 receptors → smooth muscle relaxation → vasodilation
    • Respiratory: M3 receptors → smooth muscle contraction → bronchoconstriction
    • 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: M1 receptors → increase gastric acid secretion 
    • Intestine: M3 receptors → increase peristalsis, contract the gastroesophageal sphincter, and relax the pyloric sphincter
    • Eye: M3 receptors → pupillary constriction (miosis)
    • Heart: M2 receptors lead to:
      • ↓ Heart rate due to sinoatrial (SA) node suppression
      • ↓ Conduction velocity and increased refractory period in the atrioventricular (AV) node
      • ↓ Contractility (negative inotropy)
    • Genitourinary:
      • Contraction of the detrusor muscle
      • Relaxation of the trigone and internal urethral sphincter
      • Men and women: erectile tissue stimulation
  • Nicotinic cholinergic receptors:
    • Ionotropic: act on ion channel receptors (e.g., calcium channels) (do not confuse with inotropic):
      • Receptor is activated →  ion channel opens → net Na+ influx → depolarization at the postsynaptic membrane 
      • Action potential in muscle fiber → muscle contracts
    • Located at the neuromuscular junction → skeletal muscle contraction
Cholinergic terminal neurotransmission and effects of cholinomimetic drugs

Cholinergic terminal neurotransmission Neurotransmission The junction between 2 neurons is called a synapse. The synapse allows a neuron to pass an electrical or chemical signal to another neuron or target effector cell. The plasma membranes of the 2 neurons are placed very close together, and the space between the 2 neurons is called the synaptic cleft. The molecules that mediate the interaction are called neurotransmitters. Synapses and Neurotransmission and the effects of cholinomimetic drugs:
Acetylcholine (ACh) is released into the synaptic cleft, the choline transporter (CHT) uptakes choline into the presynaptic neuron, and the vesicular ACh transporter (VAChT) uptakes ACh into the storage vesicle.
Nondepolarizing neuromuscular blockers Neuromuscular blockers Neuromuscular blockers are skeletal muscle relaxant medications that block muscle contraction through a couple of mechanisms. Depolarizing neuromuscular blockers bind to nicotinic cholinergic receptors (nAChRs), locking the ion channel open. This results in muscle relaxation and paralysis. Neuromuscular Blockers (NMBs) antagonize nicotinic receptors at neuromuscular junctions. Rocuronium is used in anesthesia Anesthesia Anesthesiology is the field of medicine that focuses on interventions that bring a state of anesthesia upon an individual. General anesthesia is characterized by a reversible loss of consciousness along with analgesia, amnesia, and muscle relaxation. Anesthesiology: History and Basic Concepts. Lambert-Eaton myasthenic syndrome Lambert-Eaton Myasthenic Syndrome Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder affecting the neuromuscular junction and has a strong association with small cell lung carcinoma. Lambert-Eaton myasthenic syndrome affects the voltage-gated calcium channels at the presynaptic membrane. Lambert-Eaton Myasthenic Syndrome ( LEMS LEMS Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder affecting the neuromuscular junction and has a strong association with small cell lung carcinoma. Lambert-Eaton myasthenic syndrome affects the voltage-gated calcium channels at the presynaptic membrane. Lambert-Eaton Myasthenic Syndrome) produces autoantibodies blocking presynaptic calcium (Ca+) channels, causing decreased ACh release into the synaptic cleft and muscle weakness. Pyridostigmine is an AChE inhibitor used to treat myasthenia gravis Myasthenia Gravis Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and fatigability of skeletal muscles caused by dysfunction/destruction of acetylcholine receptors at the neuromuscular junction. MG presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs, leading to difficulty in movement. Myasthenia Gravis. Nicotine (in cigarettes) agonizes and varenicline (used for smoking cessation support) partially agonizes nicotinic ACh receptors. Succinylcholine, a depolarizing NMB, agonizes ganglionic nicotinic receptors, leading to receptor desensitization and neuromuscular blockade. Donepezil (for dementia) inhibits the breakdown of ACh, leading to ↑ ACh in the synaptic cleft. Cholinomimetics (e.g., bethanechol for neurogenic bladder) and pilocarpine agonize muscarinic receptors.
Na+/K+ channel: sodium/potassium channel

Image by Lecturio.

Classification and Pharmacokinetics

Cholinomimetic drugs either act directly on cholinergic receptors or inhibit AChE (the enzyme breaking down ACh). Important points about the pharmacokinetic properties of the medications include onset, duration, metabolism, and availability.

Classification

  • ACh:
    • Both muscarinic and nicotinic actions
    • Rapidly hydrolyzed by AChE
  • Some agents stimulate either the nicotinic or the muscarinic receptors.
  • Direct-acting cholinomimetics:
    • Choline esters
      • ACh
      • Bethanechol
      • Methacholine
    • Plant alkaloids:
      • Nicotine
      • Muscarine
      • Pilocarpine
  • AChE inhibitors are indirect-acting cholinomimetics (AChE inhibiting, causing a net-positive cholinergic effect):
    • Reversible:
      • Donepezil and rivastigmine (used in the treatment of Alzheimer disease Alzheimer disease As the most common cause of dementia, Alzheimer disease affects not only many individuals but also their families. Alzheimer disease is a progressive neurodegenerative disease that causes brain atrophy and presents with a decline in memory, cognition, and social skills. Alzheimer Disease)
      • Neostigmine and physostigmine (used to reverse the effects of anesthesia Anesthesia Anesthesiology is the field of medicine that focuses on interventions that bring a state of anesthesia upon an individual. General anesthesia is characterized by a reversible loss of consciousness along with analgesia, amnesia, and muscle relaxation. Anesthesiology: History and Basic Concepts/neuromuscular blockade)
      • Pyridostigmine (used in the treatment of myasthenia gravis Myasthenia Gravis Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and fatigability of skeletal muscles caused by dysfunction/destruction of acetylcholine receptors at the neuromuscular junction. MG presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs, leading to difficulty in movement. Myasthenia Gravis)
    • Irreversible:
      • Malathion (antiparasitic for lice)
      • Isoflurophate (in eyedrops for glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma)
      • Sarin (used in nerve gas for bioterrorism)

Pharmacokinetics

Table: Onset and duration of AChE inhibitors
Drug Onset Duration
Neostigmine (reversible) 10–15 minutes 1–2 hours
Physostigmine (reversible) 3–8 minutes 45–60 minutes
Pyridostigmine (reversible) Oral myasthenia gravis Myasthenia Gravis Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and fatigability of skeletal muscles caused by dysfunction/destruction of acetylcholine receptors at the neuromuscular junction. MG presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs, leading to difficulty in movement. Myasthenia Gravis: 30–45 minutes Oral: 3–6 hours
IV myasthenia gravis Myasthenia Gravis Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and fatigability of skeletal muscles caused by dysfunction/destruction of acetylcholine receptors at the neuromuscular junction. MG presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs, leading to difficulty in movement. Myasthenia Gravis: 2–5 minutes IV: 2–3 hours
IV = intravenous
Table: Bioavailability and metabolism of AChE inhibitors
Drug Bioavailability Metabolism
Central AChE inhibitors
Donepezil (reversible)
  • Well absorbed orally
  • Bioavailability: 100%
  • Hepatic CYP3A4
  • Hepatic CYP2D6
  • Glucuronidation
Rivastigmine (reversible)
  • Rapid oral absorption
  • Bioavailability: approximately 40%
Inactivated by cholinesterases
Peripheral AChE inhibitors
Neostigmine (reversible) Poor oral absorption
  • Inactivated by cholinesterases
  • Hepatic metabolism
Physostigmine (reversible) Inactivated by cholinesterases
Pyridostigmine (reversible)
  • Inactivated by cholinesterases
  • Hepatic metabolism
Sialogogues
Pilocarpine Readily absorbed orally Inactivated by cholinesterases
Prokinetic/promotility agent
Bethanechol Poor oral absorption Not susceptible to degradation by cholinesterases

Clinical Indications

Cholinomimetic drugs are used to treat many conditions, including dementia, glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma, and as an aid in smoking cessation.

Table: Muscarinic agonists
Drug Mechanism Indications
Bethanechol
  • Stimulation of cholinergic muscarinic receptor on the detrusor muscle → detrusor contraction
  • Stimulation of cholinergic muscarinic receptor in the GI tract → increases gastric motility
  • ↑ Pressure in the lower esophageal sphincter
  • Neurogenic bladder
  • Urinary retention
Carbachol Direct stimulation of muscarinic receptor in the eye → constriction of ciliary muscle and contraction of iris → ↑ aqueous humor outflow → ↓ intraocular pressure (IOP) Miosis for surgery (intraocular injection)
Pilocarpine
  • Stimulates secretion of exocrine glands
  • Direct stimulation of muscarinic receptor in the eye → ↓ IOP
  • Oral forms treat xerostomia.
  • Ophthalmic drops ↓ IOP and treat glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma and mitosis induction.
Methacholine Inhaled → stimulates muscarinic receptors on bronchial smooth muscle → airway contraction Diagnostic test for asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma
Table: Nicotinic agonists
Drug Mechanism Indications
Nicotine
  • Activates mesolimbic dopamine (reward) pathway
  • Stimulates nicotinic receptors at the autonomic ganglia → peripheral effects (e.g., tachycardia, diaphoresis, and nausea) decline with repeated doses
Smoking cessation
Succinylcholine Stimulates motor endplate ACh receptors Neuromuscular blockade induction and maintenance ( anesthesia Anesthesia Anesthesiology is the field of medicine that focuses on interventions that bring a state of anesthesia upon an individual. General anesthesia is characterized by a reversible loss of consciousness along with analgesia, amnesia, and muscle relaxation. Anesthesiology: History and Basic Concepts)
Varenicline (Chantix)
  • Alleviates nicotine withdrawal symptoms by partial agonism of nicotinic receptors
  • Antagonist in the presence of nicotine
Most effective monotherapy for smoking cessation
Table: Acetylcholinesterase inhibitors
Drug Mechanism Indications
Donepezil (Aricept) AChE inhibitor Treatment of Alzheimer dementia (all stages)
Galantamine (generic) AChE inhibitor and nicotinic receptor modulator Treatment of mild-to-moderate Alzheimer dementia
Neostigmine AChE inhibitor
  • NMB reversal
  • Requires coadministration of anticholinergic Anticholinergic Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs agent (e.g., glycopyrrolate) to prevent bradycardia
Physostigmine (unavailable until end of 2022) AChE inhibitor
  • Treatment of anticholinergic Anticholinergic Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs syndrome
  • NMB reversal
Pyridostigmine AChE inhibitor
  • Treatment of myasthenia gravis Myasthenia Gravis Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and fatigability of skeletal muscles caused by dysfunction/destruction of acetylcholine receptors at the neuromuscular junction. MG presents with fatigue, ptosis, diplopia, dysphagia, respiratory difficulties, and progressive weakness in the limbs, leading to difficulty in movement. Myasthenia Gravis
  • Military preexposure prophylaxis for organophosphate (nerve gas) exposure
  • Nondepolarizing NMB reversal
  • Requires coadministration of anticholinergic Anticholinergic Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs agent (e.g., glycopyrrolate) to prevent bradycardia
Rivastigmine AChE inhibitor
  • Mild-to-moderate Alzheimer dementia
  • Dementia of Parkinson disease
AChE: acetylcholinesterase
NMB: neuromuscular blockade

Adverse Effects and Contraindications

The primary adverse effects of cholinergic drugs are the consequence of overstimulation of the parasympathetic nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). It is divided according to its anatomical components as well as its functional characteristics. The brain and spinal cord are referred to as the central nervous system, and the branches of nerves from these structures are referred to as the peripheral nervous system. General Structure of the Nervous System. Symptoms result from excessive levels of ACh in the synapses, glands, smooth muscles, and motor endplates.

Adverse effects

  • Cholinomimetic hyperactivity may result in cholinergic crisis = the same signs and symptoms seen with cholinesterase inhibitor poisoning (nerve gas):
    • Organophosphates inhibit AChE.
    • Reversed by atropine 
    • Symptoms are more severe than the usual side effects of medications:
      • Decreased blood pressure
      • GI: abdominal cramps, 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, and vomiting
      • Blurred vision
      • Pallor
      • Twitching of the facial muscles
  • Mnemonics to remember cholinergic effects:
    • Cholinomimetic muscarinic agonists exert side effects remembered by the mnemonic “SLUDGE“:
      • Salivation                                     
      • Lacrimation
      • Urination                             
      • Defecation/ 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
      • Gastric Emptying
    • Also “BBB“:
      • Bradycardia
      • Bronchoconstriction
      • Bronchorrhea (excess mucus discharge)
  • Side effects of AChE inhibitors (e.g., donepezil):
    • Most common: 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
    • AV block AV block Atrioventricular (AV) block is a bradyarrhythmia caused by delay, or interruption, in the electrical conduction between the atria and the ventricles. Atrioventricular block occurs due to either anatomic or functional impairment, and is classified into 3 types. Atrioventricular Block
    • Bradycardia
    • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
    • GI bleed
    • Headache
    • 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
    • Mood disturbance (e.g., depression and anxiety)

Contraindications

  • AChE inhibitors:  
    • Cardiac conduction defects (risk of QT prolongation causing ventricular tachycardia Ventricular tachycardia Ventricular tachycardia is any heart rhythm faster than 100 beats/min, with 3 or more irregular beats in a row, arising distal to the bundle of His. Ventricular tachycardia is the most common form of wide-complex tachycardia, and it is associated with a high mortality rate. Ventricular Tachycardia)
    • Asthma or chronic obstructive pulmonary disease Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by progressive, largely irreversible airflow obstruction. The condition usually presents in middle-aged or elderly persons with a history of cigarette smoking. Signs and symptoms include prolonged expiration, wheezing, diminished breath sounds, progressive dyspnea, and chronic cough. Chronic Obstructive Pulmonary Disease (COPD) ( COPD COPD Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by progressive, largely irreversible airflow obstruction. The condition usually presents in middle-aged or elderly persons with a history of cigarette smoking. Signs and symptoms include prolonged expiration, wheezing, diminished breath sounds, progressive dyspnea, and chronic cough. Chronic Obstructive Pulmonary Disease (COPD))
    • Urinary tract obstruction Urinary tract obstruction Urinary tract obstruction (UTO) refers to the blockage of the urinary tract, which can occur anywhere in the urinary tract. Urinary tract obstruction can be acute or chronic, partial or complete, and unilateral or bilateral. Urinary tract obstruction can cause acute or chronic kidney disease. Urinary Tract Obstruction
    • Seizure history or risk
    • GI bleed history or risk
  • Pilocarpine: Use eye drops to treat glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma and oral tablets to treat xerostomia (e.g., Sjögren syndrome):
    • Contraindicated in angle-closure glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
    • Acute iritis 
    • Acute asthma Asthma Asthma is a chronic inflammatory respiratory condition characterized by bronchial hyperresponsiveness and airflow obstruction. The disease is believed to result from the complex interaction of host and environmental factors that increase disease predisposition, with inflammation causing symptoms and structural changes. Patients typically present with wheezing, cough, and dyspnea. Asthma
    • Use caution with hepatic impairment.

Comparison Table

Table: Comparison of cholinomimetics
Drug Mechanism Indications Contraindications
Bethanechol Direct-acting choline ester
  • Xerostomia
  • Urinary retention
  • Diabetic neuropathy
  • Asthma
  • Coronary insufficiency
  • Peptic ulcer Peptic ulcer Peptic ulcer disease (PUD) refers to the full-thickness ulcerations of duodenal or gastric mucosa. The ulcerations form when exposure to acid and digestive enzymes overcomes mucosal defense mechanisms. The most common etiologies include Helicobacter pylori (H. pylori) infection and prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs). Peptic Ulcer Disease
  • Hyperthyroidism Hyperthyroidism Thyrotoxicosis refers to the classic physiologic manifestations of excess thyroid hormones and is not synonymous with hyperthyroidism, which is caused by sustained overproduction and release of T3 and/or T4. Graves' disease is the most common cause of primary hyperthyroidism, followed by toxic multinodular goiter and toxic adenoma. Thyrotoxicosis and Hyperthyroidism
Pilocarpine Direct-acting plant alkaloid
  • Xerostomia
  • Dry eye
  • Testing for cystic fibrosis Cystic fibrosis Cystic fibrosis is an autosomal recessive disorder caused by mutations in the gene CFTR. The mutations lead to dysfunction of chloride channels, which results in hyperviscous mucus and the accumulation of secretions. Common presentations include chronic respiratory infections, failure to thrive, and pancreatic insufficiency. Cystic Fibrosis
Pregnancy Pregnancy Pregnancy is the time period between fertilization of an oocyte and delivery of a fetus approximately 9 months later. The 1st sign of pregnancy is typically a missed menstrual period, after which, pregnancy should be confirmed clinically based on a positive β-hCG test (typically a qualitative urine test) and pelvic ultrasound. Pregnancy: Diagnosis, Maternal Physiology, and Routine Care
Donepezil Reversible cholinesterase inhibitor
  • Alzheimer disease Alzheimer disease As the most common cause of dementia, Alzheimer disease affects not only many individuals but also their families. Alzheimer disease is a progressive neurodegenerative disease that causes brain atrophy and presents with a decline in memory, cognition, and social skills. Alzheimer Disease
  • Lewy body dementia
  • Traumatic brain injury
  • Peptic ulcer Peptic ulcer Peptic ulcer disease (PUD) refers to the full-thickness ulcerations of duodenal or gastric mucosa. The ulcerations form when exposure to acid and digestive enzymes overcomes mucosal defense mechanisms. The most common etiologies include Helicobacter pylori (H. pylori) infection and prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs). Peptic Ulcer Disease
  • Asthma
  • Neuroleptic malignant syndrome Neuroleptic malignant syndrome Neuroleptic malignant syndrome (NMS) is a rare, idiosyncratic, and potentially life-threatening reaction to antipsychotic drugs. Neuroleptic malignant syndrome presents with ≥ 2 of the following cardinal symptoms: fever, altered mental status, muscle rigidity, and autonomic dysfunction. Neuroleptic Malignant Syndrome
  • AV block AV block Atrioventricular (AV) block is a bradyarrhythmia caused by delay, or interruption, in the electrical conduction between the atria and the ventricles. Atrioventricular block occurs due to either anatomic or functional impairment, and is classified into 3 types. Atrioventricular Block
Neostigmine Reversible cholinesterase inhibitor
  • Myasthenia gravis
  • Reverse muscle relaxant
  • Mechanical GI obstruction
  • Urinary obstruction
Pyridostigmine Reversible cholinesterase inhibitor
  • Myasthenia gravis
  • Orthostatic 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
  • Mechanical GI obstruction
  • Urinary obstruction
Malathion Irreversible cholinesterase inhibitor
  • Lice
  • Scabies Scabies Scabies is an infestation of the skin by the Sarcoptes scabiei mite, which presents most commonly with intense pruritus, characteristic linear burrows, and erythematous papules, particularly in the interdigital folds and the flexor aspects of the wrists. Scabies
  • Infants
  • Neonates
AV: atrioventricular

References

  1. Neurotransmitters and Neuromodulators. In: Nelson, L.S., Howland, M., Lewin, N.A., Smith, S.W., Goldfrank, L.R., Hoffman, R.S. Goldfrank’s Toxicologic Emergencies, 11e. New York, NY: McGraw-Hill, 2019.
  2. IBM Micromedex® DRUGDEX® (electronic version). IBM Watson Health, Greenwood Village, Colorado, USA. Retrieved October 7, 2021, from https://www.micromedexsolutions.com
  3. Arvanitakis, Z., Shah, R.C., & Bennett, D.A. (2019). Diagnosis and management of dementia: Review. JAMA. 322(16), pp. 1589–1599. https://doi.org/10.1001/jama.2019.4782 
  4. 2019 American Geriatrics Society Beers Criteria Update Expert Panel (2019). American Geriatrics Society 2019 updated AGS Beers criteria® for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society. https://doi.org/10.1111/jgs.15767 
  5. Rickey, L.M. (2019). Chronic urinary retention in women. UpToDate. Retrieved October 7, 2021, from https://www.uptodate.com/contents/chronic-urinary-retention-in-women
  6. Lexicomp, Inc. (2021). Donepezil and memantine: Drug information. UpToDate. Retrieved October 7, 2021, from https://www.uptodate.com/contents/donepezil-and-memantine-drug-information
  7. Lexicomp, Inc. (2021). Pilocarpine (systemic): Drug information. UpToDate. Retrieved October 7, 2021, from https://www.uptodate.com/contents/pilocarpine-systemic-drug-information

Study on the Go

Lecturio Medical complements your studies with evidence-based learning strategies, video lectures, quiz questions, and more – all combined in one easy-to-use resource.

Learn even more with Lecturio:

Complement your med school studies with Lecturio’s all-in-one study companion, delivered with evidence-based learning strategies.

User Reviews

0.0

()

¡Hola!

Esta página está disponible en Español.

🍪 Lecturio is using cookies to improve your user experience. By continuing use of our service you agree upon our Data Privacy Statement.

Details