Antihypertensive Risk

• Minoxidil tablets contain the powerful antihypertensive agent, minoxidil, which may produce serious adverse effects. It can precipitate effusion, occasionally progressing to tamponade, and angina pectoris may be exacerbated. Minoxidil should be reserved for hypertensive patients who do not respond adequately to maximum therapeutic doses of a diuretic and two other antihypertensives.
• In experimental animals, minoxidil caused several kinds of myocardial lesions as well as other adverse cardiac effects (See Package Insert: Cardiac Lesions in Animals).
• Minoxidil must be administered under close supervision, usually concomitantly with therapeutic doses of a beta-adrenergic blocking agent to prevent tachycardia and increased myocardial workload. It must also usually be given with a diuretic, frequently one acting in the descending limb of the loop of Henle, to prevent serious fluid accumulation. Patients with malignant hypertension and those already receiving guanethidine (See Warnings) should be hospitalized when minoxidil is first administered so that they can be monitored to avoid too rapid or large orthostatic, decreases in blood pressure.