minoxidil (topical)
Minoxidil for Men, Rogaine, Rogaine Extra Strength for Men, Rogaine for Women

Available forms
Available without a prescription
Topical solution: 2%, 5% in 60-ml bottle

Indications and dosages
 Male-pattern baldness (alopecia androgenetica), diffuse hair loss or thinning in women, adjunct to hair transplantation ◇. Adults: Apply 1 ml of 2% or 5% solution to affected area b.i.d.
 Alopecia areata ◇. Adults: 1 ml of 1%, 3%, or 5% solution applied to scalp b.i.d.

Pharmacodynamics
Hair-growth stimulation action: Unknown. It may alter androgen metabolism in the scalp, or it may exert a local vasodilatation and enhance the microcirculation around the hair follicle. It may also directly stimulate the hair follicle.

Pharmacokinetics
Absorption: Poorly absorbed through intact skin. About 0.3% to 4.5% of a topically applied dose reaches the systemic circulation. Application to skin with decreased integrity may increase systemic absorption.
Distribution: Serum levels are generally negligible.
Metabolism: Metabolism isn’t fully described.
Excretion: Eliminated primarily by the kidneys. About 95% of a topically applied dose is eliminated after 4 days.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug or its components and in pregnant women. Use cautiously in patients with renal, cardiac, or hepatic disease; those older than age 50; and breast-feeding women.

Interactions
Drug-drug. Topical corticosteroids, petrolatum, retinoids: May increase absorption when used in same area. Use together cautiously.

Adverse reactions
CNS: headache, dizziness, faintness, light-headedness.
CV: edema, chest pain, hypertension, hypotension, palpitations, increased or decreased pulse rate, heart failure.
EENT: sinusitis.
GI: diarrhea, nausea, vomiting.
GU: urinary tract infection, renal calculi, urethritis.
Metabolic: weight gain.
Musculoskeletal: back pain, tendinitis.
Respiratory: bronchitis, upper respiratory infection.
Skin: irritant dermatitis, allergic contact dermatitis, eczema, hypertrichosis, local erythema, pruritus, dry skin or scalp, flaking, alopecia, exacerbation of hair loss.

Effects on lab test results
None reported.

Overdose and treatment
None reported. However, if topical use produces systemic adverse effects, wash application site thoroughly with soap and water and treat symptoms, as appropriate. Signs and symptoms of oral overdose include hypotension, tachycardia, headache, and skin flushing.
 After acute ingestion, empty stomach by induced emesis or gastric lavage, and give activated charcoal to reduce absorption. Further treatment is usually symptomatic and supportive.

Special considerations
• Before treatment with topical minoxidil, patient should give a history, have a physical examination, and be advised of potential risks; a risk-benefit decision should be made. Patients with cardiac disease should realize that adverse effects may be especially serious. Alert patient to possibility of tachycardia and fluid retention, and monitor patient for increased heart rate, weight gain, or other systemic effects.
• Before starting treatment, check that patient has a normal, healthy scalp. Local abrasion or dermatitis may increase absorption and the risk of adverse effects.
• Don’t use with other topical agents, such as corticosteroids, retinoids, and petrolatum, or agents that enhance percutaneous absorption. Rogaine is for topical use only; each ml contains 20 or 50 mg minoxidil and accidental ingestion could cause adverse systemic effects.
• Alcohol base will burn and irritate sensitive surfaces (eye, abraded skin, and mucous membranes). If topical minoxidil contacts sensitive areas, flush with copious cool water.
• The 5% topical solution shouldn’t be used by women.
• Self-medication should cease if no hair grows in 8 months for women and 12 months for men using the 2% solution and in 4 months in men using the 5% solution.
• Monitor patient 1 month after starting topical drug therapy and at least every 6 months afterward. Discontinue topical minoxidil if systemic effects occur.
Breast-feeding patients
• Don’t administer topical minoxidil to breast-feeding women.
Pediatric patients
• Safety and efficacy haven’t been established for patients younger than age 18.

Patient education
• Tell patient to avoid inhaling the spray.
• Teach patient to apply topical minoxidil as follows: Dry hair and scalp. Apply 1 ml to the total affected areas twice daily. Total daily dose shouldn’t exceed 2 ml. If fingertips are used to apply the drug, wash hands afterward.
• Encourage patient to carefully review patient information leaflet, which is included with each package and in the full product information.
• Inform patient that 4 months of use may be required before results become apparent.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use