minoxidil: clinical use

Prescribing considerations

• Confirm androgenetic alopecia before topical treatment; investigate sudden, patchy, postpartum or unexplained loss and systemic or nutritional causes.
• Reserve oral minoxidil for severe hypertension within combination therapy and close follow-up.
• Oral use for hair loss is off-label and should involve benefit-risk discussion and appropriate monitoring.

Contraindications and cautions

• Hypersensitivity to minoxidil or relevant excipients.
• Selected topical products: treated or untreated hypertension, abnormal or damaged scalp, occlusive dressings or other topical scalp medicines; restrictions vary by product.
• Oral tablets: phaeochromocytoma.

Monitoring

• Oral treatment: blood pressure, pulse, body weight, fluid and electrolyte balance, oedema and renal function.
• Watch for heart failure, angina, pericarditis, pericardial or pleural effusion and clinically significant ECG changes.
• Topical treatment: review persistent scalp inflammation, hypotension, cardiovascular symptoms, oedema or unexplained weight gain.

Clinical pharmacology

Topical absorption through intact skin is low. Oral minoxidil is extensively absorbed; its vasodilation activates reflex sympathetic and renin–angiotensin–aldosterone responses.

Formulation and product differences

• Topical product licences, contraindications and applicators are formulation-specific and should not be assumed interchangeable.
• Selected topical products differ in their minoxidil concentration and excipients, including ethanol and, in some products, propylene glycol.

Cutaneous foam

Route: Cutaneous

Strengths: 5% w/w

Cutaneous spray

Route: Cutaneous

Strengths: 5% w/v

Tablet

Route: Oral

Strengths: 2.5 mg, 5 mg, 10 mg