Oral Severe hypertension unresponsive to standard therapy
Adult: In conjunction w/ a β-blocker or methyldopa, and a diuretic: Initially, 5 mg daily, gradually increase at intervals of at least 3 days to 40 mg or 50 mg as a single or in 2 divided doses daily depending on response. Max: 100 mg daily. For rapid control of BP: Dose increments of 5 mg 6 hrly may be given w/ careful monitoring. Child: ≤12 yr In conjunction w/ a β-blocker or methyldopa, and a diuretic: Initially, 200 mcg/kg daily in 1 or 2 divided doses w/ increments of 100-200 mcg/kg at intervals of at least 3 days according to response. Max: 1 mg/kg or 50 mg daily. Elderly: Initially, 2.5 mg daily, increase gradually.
Topical/Cutaneous Male pattern baldness
Adult: Male: As 2% or 5% soln: Apply 1 mL to the scalp bid. As 5% foam or aerosol: Apply ½ capful to the scalp bid. Female: As 2% soln: Apply 1 mL to the scalp bid. As 5% foam or aerosol: Apply ½ capful to the scalp once daily.
Initiate at smaller doses or at longer dosage intervals.
Monitor BP, fluid and electrolytes, body wt, signs/symptoms of pericardial effusion, renal function.
Symptoms: Exaggerated hypotension. Management: Admin IV normal saline. Phenylephrine, angiotensin II and vasopressin may be given if inadequate perfusion of a vital organ is evident.
Additive effect w/ other hypotensive drugs. Risk of orthostatic hypotension w/ sympathetic blocking drugs (e.g. guanethidine). Topical: Enhanced absorption w/ other topical medical preparations (e.g. corticosteroids, retinoids or occlusive ointment bases).
Description: Minoxidil reduces elevated systolic and diastolic BP by decreasing peripheral vascular resistance via vasodilation. Applied topically, it stimulates hair growth secondary to vasodilation, increases cutaneous blood flow and stimulates resting hair follicles. Onset: Approx 30 min (oral). Duration: Approx 3 days (oral). Pharmacokinetics: Absorption: Approx 90% is absorbed from the GI tract (oral); 0.3-4.5% from intact scalp (topical). Distribution: Enters breast milk. Metabolism: Extensively hepatic via glucuronidation. Excretion: Via urine as metabolites. Elimination half-life: Approx 4.2 hr.