Vasodilators – Heart Failure and Angina Management

Hypertension has consistently made its way to the leading causes of morbidity and mortality in recent years. Millions of deaths and disabilities are being documented worldwide because of its complications, such as cerebrovascular accidents and ischemia in various locations in the body. Despite its notorious nature, hypertension is preventable and controllable. This is made possible by making use of various pharmacologic managements that are available today. One of the most common medications used to control blood pressure is a direct vasodilator.

Diuretics promote the generation of a negative fluid balance in the body. Additionally, nearly all diuretics increase the excretion of sodium in the kidneys, so that water is linked osmotically and also excreted. The different diuretics affect different parts of the tubule system.

Thiazide diuretics are some of the most common diuretics currently in use. Their mechanism of action involves inhibition of the Na/Cl co-transporter channel in the proximal part of the distal convoluted tubule, leading to increased sodium and chloride secretion. Their effects on reducing peripheral vascular resistance further contribute to their antihypertensive properties, in addition to their ability in decreasing effective blood volume. Besides hypertension, they are indicated for the treatment of heart failure exacerbation, hypercalciuria and diabetes insipidus. Important side effects include hypokalemia, hypercalcemia, hyponatremia, hyperglycemia, hyperuricemia and hypomagnesemia.  

Loop diuretics are one of the important classes of diuretics. Furosemide is the most commonly used loop diuretics. Other loop diuretics used are bumetanide, torasemide and ethacrynic acid. Loop diuretics are the most efficacious in causing diuresis in all the classes of diuretics. All the loop diuretics have the same mechanism of action, but different pharmacokinetic properties. They are used to treat/manage numerous diseases such as edema associated with CHF and liver cirrhosis. Diuretics most commonly cause electrolyte imbalance in the body on prolonged use.

Hypertension is the rise in blood pressure beyond the defined set point (conventionally ≥ 140/90 mmHg). Hypertension is the known risk factor for a number of cardiovascular events like myocardial infarction, angina and heart failure, sudden cardiac death. The pharmacological therapy for hypertension is discussed in this section. The therapies have evolved over time and the current line of therapy offers tremendous response and decreases the morbidity and mortality associated with this condition. It should be noted that non-pharmacological therapy like exercise and healthy food habits also play an important part in controlling hypertension.