Primary Vasodilators

Hydralazine and minoxidil are both vasodilators, which help reduce blood pressure by reducing preload and afterload from venous and arteriolar relaxation, respectively.  Hydralazine is used to treat hypertension including hypertensive emergencies and pregnancy induced hypertension.  Hydralazine is noted to cause a reversible Lupus-like syndrome. Minoxidil is mainly used for treatment of male pattern baldness.

Class Drugs

• Hydralazine

• Minoxidil

Class Mechanism of Action

Relaxation of vascular smooth muscle

• Decreases preload via increased venous capacity

• Decreases afterload via arteriolar relaxation

Class Applications

Hypertension

Class Adverse Effects

• See individual drugs

• Reflex tachycardia and increased myocardial contraction can occur due to sudden drop in pre-load

May lead to coronary ischemia, heart failure, etc.

Drug Table

Drug Name	Application	Comments	Image
Hydralazine	Hypertension; Pregnancy induced hypertension; Hypertensive emergency	Adverse Effects; -Headache; -Arrhythmia; -Reversible Lupus-like syndrome	"Fire Hydrant" "Lay-Z-Boy"
Minoxidil	Male pattern baldness (topically)	Adverse Effects; -Hypertrichosis	"Minnow" "Dill Pickle"