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Uses

Hypertension

Management of severe symptomatic hypertension or hypertension associated with end-organ damage in patients with uncontrolled hypertension not manageable with maximal therapeutic dosages of a diuretic and 2 other antihypertensive agents.

Not recommended for mild or moderate hypertension or severe hypertension controllable with other drugs.

Often effective in management of hypertension resistant to other drugs.

May be used in combination with other antihypertensive therapies (e.g., a diuretic and a β-adrenergic blocking agent, an ACE inhibitor, a calcium-channel blocking agent, and/or an angiotensin II receptor antagonist).

Do not use for the treatment of hypertension in patients with left ventricular hypertrophy.

Androgenetic Alopecia

Used topically to stimulate regrowth of hair in patients with androgenetic alopecia (male pattern alopecia, hereditary alopecia, common male baldness) or alopecia areata†. Safety and efficacy of extemporaneously prepared formulations of topical minoxidil in promoting hair growth not fully evaluated and such preparations may vary in strength and efficacy. FDA requests that physicians and pharmacists refrain from preparing extemporaneous topical formulations using the commercially available tablets.

Dosage and Administration

General

• A β-adrenergic blocking agent (equivalent to 80–160 mg of propranolol daily) must be given before initiation of minoxidil therapy and continued for duration of therapy, to minimize minoxidil-induced tachycardia and increased myocardial workload. If a β-adrenergic blocking agent is contraindicated, methyldopa (250–750 mg twice daily) should be initiated at least 24 hours prior to minoxidil therapy; clonidine (0.1–0.2 mg twice daily) may be used as an alternative.
• A thiazide or loop diuretic must be used in patients dependent on renal function for maintenance of sodium and water balance.
• Once therapy initiated, adjust dosage carefully according to individual requirements and BP response at approximately monthly intervals or more aggressively in high-risk patients.

Administration

Oral Administration

Administer orally once daily if patient’s supine DBP has been reduced by <30 mm Hg; administer twice daily (in equally divided doses) if patient’s supine DBP reduced >30 mm Hg.

If rapid control needed, may give dose every 6 hours; monitor BP closely.

Dosage

Pediatric Patients

Hypertension

Oral

Children <12 years of age: Initially, 0.2 mg/kg (not to exceed 5 mg) once daily.

Dosages may be increased at intervals of at least 3 days in increments of 50–100% until optimum BP response is achieved. If rapid control needed, adjust dosage every 6 hours; monitor BP closely.

Usual effective dosage is 0.25–1 mg/kg daily in 1 or 2 doses up to a maximum dosage of 50 mg daily.

Children >12 years of age: Initially, 2.5–5 mg once daily. Dosages may be increased at intervals of least 3 days to 10 mg, 20 mg, and then 40 mg daily in 1 or 2 divided doses until optimum BP response is achieved. If rapid control needed, adjust dosage every 6 hours; monitor BP closely.

Usual effective dosage is 10–40 mg daily in 1 or 2 doses up to maximum dosage of 100 mg daily.

Some experts (JNC 7) recommend a usual dosage of 2.5–80 mg daily given in 1 or 2 divided doses daily.

Severe Hypertension

Oral

Pediatric patients 1–17 years of age: For rapid reduction of blood pressure, 0.1–0.2 mg/kg may be used.†

Adults

Hypertension

Oral

Initially, 2.5–5 mg once daily. Dosages may be increased at intervals of least 3 days to 10 mg, 20 mg, and then 40 mg daily in 1 or 2 divided doses until optimum BP response is achieved.If rapid control needed, adjust dosage every 6 hours; monitor BP closely.

Usual effective dosage is 10–40 mg daily in 1 or 2 doses up to maximum dosage of 100 mg daily.

Some experts (JNC 7) recommend a usual dosage of 2.5–80 mg daily given in 1 or 2 divided doses.

Prescribing Limits

Pediatric Patients

Hypertension

Oral

Children <12 years of age: maximum 50 mg daily.

Children >12 years of age: maximum 100 mg daily.

Adults

Hypertension

Oral

Maximum 100 mg daily.

Special Populations

Dosage in Renal Impairment

Lower dosage may be required in renal failure or dialysis (about (1/3) less than in patients who are not receiving dialysis).

Removed during dialysis. Some clinicians recommend administering minoxidil immediately after dialysis (if dialysis is at 9 a.m.); if dialysis is after 3 p.m., the daily dose is given at 7 a.m. (i.e., 8 hours before dialysis).

Geriatric Patients

Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.