(Science: chemical) A potent direct-acting peripheral vasodilator that reduces peripheral resistance and produces a fall in blood pressure. It is given by mouth in the treatment of severe hypertension unresponsive to other therapy. It is also used topically in the treatment of male–pattern baldness.
Pharmacological action: antihypertensive agents, vasodilator agents.
Chemical name: 2,4-Pyrimidinediamine, 6-(1-piperidinyl)-, 3-oxide