Doxycycline Dosing for Acne Treatment
For adults and patients over 100 pounds with acne, the recommended dose of doxycycline is 200 mg on the first day (given as 100 mg every 12 hours), followed by a maintenance dose of 100 mg daily. 1
Dosing Guidelines by Weight and Age
Adults and Children >100 pounds:
- Initial dose: 200 mg on day 1 (administered as 100 mg every 12 hours)
- Maintenance dose: 100 mg once daily
Children 8 years and older but <100 pounds:
- Initial dose: 2 mg/lb body weight divided into 2 doses on day 1
- Maintenance dose: 1 mg/lb body weight daily (can be given as single dose or divided into 2 doses)
Treatment Duration and Monitoring
- Limit systemic antibiotic use to the shortest possible duration
- Re-evaluate treatment at 3-4 months to minimize bacterial resistance development
- Do not use doxycycline as monotherapy for acne
Combination Therapy Requirements
- Always combine with topical therapy such as benzoyl peroxide or a topical retinoid
- Continue topical therapy for maintenance after completing systemic antibiotic treatment
Alternative Dosing Options
- Low-dose doxycycline (20 mg twice daily or 40 mg extended-release daily) has demonstrated efficacy in moderate inflammatory acne 1, 2
- This subantimicrobial dosing may be considered for patients with moderate acne who cannot tolerate standard doses
Important Precautions and Side Effects
- Most common side effects: gastrointestinal disturbances (15.7% vs 5.9% with placebo) 1
- Phototoxic reactions are dose-related (significantly higher incidence at doses ≥150 mg daily) 3
- Take with food and adequate fluids while in upright position to reduce GI side effects
- Avoid in pregnancy and children under 8 years (pregnancy category D)
- Distributed into breast milk; discontinue nursing or the medication
Contraindications
- Hypersensitivity to any tetracycline antibiotic
- Children under 8 years of age (risk of permanent tooth discoloration)
- Pregnancy and breastfeeding
Clinical Pearls
- Doxycycline is considered first-line therapy for moderate to severe inflammatory acne
- Higher doses (>100 mg daily) do not appear to provide additional efficacy but increase side effect risk, particularly phototoxicity 3
- Subantimicrobial dosing (20 mg twice daily) can achieve significant reduction in inflammatory lesions (84% reduction in papules, 90% reduction in pustules) 2
- Warn patients about increased sun sensitivity and advise use of sunscreen
- Avoid taking with antacids, calcium, iron, or magnesium supplements (take at least 2 hours apart)
By following these dosing guidelines and precautions, doxycycline can be an effective treatment for moderate to severe acne while minimizing potential adverse effects.