What is the recommended treatment and dosage of minoxidil for a patient with androgenetic alopecia, considering potential side effects and medical history, including cardiovascular conditions?

Minoxidil Treatment for Androgenetic Alopecia

Topical minoxidil 5% applied twice daily (1 mL per application) is the first-line treatment for androgenetic alopecia, with mandatory cardiovascular screening required before considering oral minoxidil, which should be avoided in patients with existing cardiovascular disease. 1, 2, 3

Topical Minoxidil: First-Line Therapy

Dosing and Application

• Apply 1 mL of 5% topical solution twice daily directly to the scalp in areas of hair loss 3
• Allow 2-4 hours for complete drying before washing hair or lying down 3
• Treatment must be continued indefinitely; discontinuation leads to reversal of hair growth within 3-4 months 1, 3
• Results typically appear at 2 months, though some patients require 4 months of continuous use to see improvement 3, 4

Efficacy

• The 5% solution produces 45% more hair regrowth than 2% solution at 48 weeks in men 4
• In women, 5% topical minoxidil demonstrates superiority over placebo in hair count and patient/investigator assessments, though the FDA label recommends 2% for women 5
• Peak efficacy occurs around 48 weeks of continuous treatment 3

Common Pitfalls

• Missing applications: Do not double-dose to compensate for missed applications 3
• Insufficient drying time: Ensure 4 hours of contact time before washing 3
• Premature discontinuation: Initial shedding in the first 2 weeks is expected and indicates the medication is working 3

Combination Therapy with Platelet-Rich Plasma (PRP)

For patients seeking enhanced results, combining topical minoxidil 5% with PRP injections shows superior efficacy compared to either treatment alone. 1, 6

Protocol

• Apply topical minoxidil 5% (1 mL) twice daily continuously 1
• Add PRP injections: 3-5 sessions spaced one month apart initially 1
• Use 5-7 mL of nonactivated PRP per session at 0.05-0.1 mL/cm², injected at 1 cm intervals, 2-4 mm depth 1
• Maintenance phase: one PRP session every 6 months 1
• Apply pharmaceutical-grade topical anesthetic cream before PRP injections due to significant pain 1

Expected Outcomes

• Combination therapy achieves 57% median increase in terminal hair density versus 48% with minoxidil alone at 32 weeks 1
• 83% of patients achieve negative hair pull test (reduced hair fragility) with combination therapy 1
• Nonactivated PRP shows 31% greater improvement in hair density compared to activated PRP 1

Oral Minoxidil: Second-Line Option

Oral minoxidil 1 mg daily can be considered only for patients who fail or cannot tolerate topical therapy, but requires mandatory cardiovascular screening and should be avoided in patients with cardiovascular disease. 2

Cardiovascular Screening Requirements

• Screen ALL patients for cardiovascular disease before initiating oral minoxidil 2
• Absolute contraindication: pre-existing cardiovascular disease 2
• Monitor for orthostatic symptoms, edema, tachycardia, and pericardial effusion 2
• The hypotensive effect lasts approximately 72 hours despite a 4-hour half-life 2

Dosing Considerations

• Women: Start with 1 mg daily due to higher risk of adverse effects 2
• Men: 1 mg daily is as effective as topical 5% 2
• Doses >5 mg increase adverse effects including hypertrichosis (17.5%) and tachycardia (3.5%) 2

Adverse Effects

• Overall incidence of adverse effects: 14.9% at low doses 2
• Common: hypertrichosis, dizziness, extremity edema 2
• Rare but serious: pericardial effusion, tachycardia 2
• Women have higher overall incidence of adverse effects compared to men 2

Additional Contraindications

• Pregnancy or women planning to become pregnant (lack of safety data) 2
• Age <18 years 3

Monitoring Treatment Response

Evaluation Timeline

• Assess at 3,6, and 12 months using multiple methods 2
• If no improvement after 4 months of topical therapy, discontinue 3

Assessment Tools

• Standardized before-and-after photographs 1
• Trichoscopy to evaluate hair density and diameter 1
• Hair pull tests to evaluate hair fragility 1
• Patient self-assessment questionnaires 1
• Monitor terminal versus vellus hair ratio 1

Key Indicators of Response

• Increased hair density 1
• Increased hair shaft diameter 1
• Decreased proportion of telogen hairs 1
• Improved patient satisfaction scores 1

Important Clinical Considerations

Who Should NOT Use Minoxidil

• Frontal baldness or receding hairline (minoxidil works primarily on vertex) 3
• Scalp that is red, inflamed, infected, irritated, or painful 3
• Sudden or patchy hair loss 3
• Unknown cause of hair loss 3
• No family history of hair loss 3

Compatibility with Hair Treatments

• Hair coloring, perming, and relaxers are permitted 3
• Ensure all minoxidil is washed off before chemical treatments 3
• Do not apply minoxidil on the same day as chemical treatments 3
• Wait 24 hours after chemical treatments before resuming minoxidil 3

When to Stop and Seek Medical Attention

• Chest pain, rapid heartbeat, faintness, or dizziness 3
• Sudden unexplained weight gain 3
• Hand or foot swelling 3
• Scalp irritation or redness 3
• Unwanted facial hair growth 3
• No hair regrowth after 4 months 3