Mechanism of action:
It causes dilatation of arterioles by unclosing of potassium channels. This opening of potassium channels causes hyperpolarization leading to relaxation of smooth muscles. This relaxation of smooth muscles results in the reduction of total peripheral vascular resistance. So, the blood pressure is reduced.
Minoxidil may cause palpitations and reflex tachycardia.
It may increase the plasma renin activity caused by reflex sympathetic activity or decrease by certain unknown mechanism.
It may cause sodium and water retention.
It is well absorbed orally. It is metabolized in the liver. Its duration of action is about 1-3 days.
1. Moderate to serious hypertension
2. severe hypertension associated with disturbance of renal function
3. topically can be used as an activator of hair growth for baldness
Headache, Tachycardia, angina, sweating, Excessive hair growth, fluid retention causing volume overload