Minoxidil in the management of intractable hypertension

Eighty-seven patients with intractable hypertension received minoxidil for a mean duration of 27 months (range three months to five years). A significant reduction in mean outpatient blood pressure from 206/129 to 158/98 mmHg (p less than 0.001 for both systolic and diastolic values) was recorded after one month's treatment. In 26 patients who received minoxidil for four or more years a further reduction in mean blood pressure to 147/89 mmHg was achieved. The mean daily dose of minoxidil was 23 mg (range 2.5 to 60 mg). In all patients a beta adrenergic neurone blocker and a diuretic were prescribed with minoxidil to counteract tachycardia and fluid retention. Thirteen patients required the addition of a fourth hypotensive agent. The use of minoxidil led to simpler drug regimens with the majority of patients well controlled on twice daily or once daily schedules. Most patients commented spontaneously on a feeling of improved wellbeing while taking minoxidil which also appeared to be relatively free from side effects commonly encountered with other hypotensive drugs, particularly drowsiness, dizziness and impotence. Fluid retention of 7 kg or more occurred in 18 patients, more commonly in those with renal impairment, but could be controlled by increasing the dose or potency of diuretics. Four patients with end stage renal failure and one patient with normal renal function developed pericardial effusions. Hirsutism was universal and limited the usefulness of the drug in women. We currently recommend minoxidil for hypertensive men who diastolic blood pressure remains greater than or equal to 110 mmHg despite an adequate trial of a beta adrenergic neurone blocker, diuretic and an additional drug, or for patients who find the side effects of such therapy intolerable.