Evaluation of minoxidil

Area of Science:

• Pharmacology
• Cardiovascular Medicine
• Clinical Therapeutics

Background:

• Minoxidil is a recently approved antihypertensive agent.
• It functions as an orally effective vasodilator.
• Its mechanism involves selective relaxation of peripheral arteriolar smooth muscle.

Purpose of the Study:

• To review the chemistry, pharmacokinetics, mechanism of action, clinical studies, adverse effects, toxicology, indications, contraindications, drug interactions, and dosing of minoxidil.
• To assess its efficacy and safety in managing severe hypertension.

Main Methods:

• Review of existing literature on minoxidil.
• Analysis of controlled and uncontrolled clinical studies.
• Evaluation of pharmacokinetic and pharmacodynamic properties.

Main Results:

• Minoxidil effectively lowers blood pressure in severe hypertension, including cases secondary to renal or renovascular disease and essential hypertension.
• Common adverse effects include reflex tachycardia, renin stimulation, and sodium retention, necessitating co-administration with a diuretic and a sympathoplegic agent (e.g., beta blocker).
• Other adverse effects include hirsutism and pericardial effusions.

Conclusions:

• Minoxidil is a potent antihypertensive agent effective in treatment-resistant severe hypertension.
• Its significant adverse effects limit its use to patients intolerant or unresponsive to other antihypertensive drugs.
• Concomitant use of diuretics and beta blockers is essential for managing minoxidil's side effects.