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Topical bactericidal / Anti-acne (keratolytic) Pregnancy: Considered compatible at topical doses — minimal systemic absorption. Use with caution in first trimester.

Benzoyl Peroxide 2.5–10%

Brand names: PanOxyl (2.5%, 5%, 10% gel/wash), Brevoxyl (4% cream), Duac (benzoyl peroxide 5% + clindamycin 1% — combination)

Adult dose

Dose: Apply once or twice daily to affected areas
Route: Topical (gel, cream, or wash)
Frequency: Once daily initially (increase to twice daily as tolerated)
Max: Apply to affected areas; 10% max concentration
Start with lower concentration (2.5–5%) once daily to minimise irritation. Increase to 5–10% and twice daily after 2–4 weeks if tolerated. Bactericidal against C. acnes (not antibiotic — no resistance). Also keratolytic. Key role in combination to prevent antibiotic resistance.

Paediatric dose

Route: Topical
Frequency: Once daily
Max: 2.5–5% in children; 10% in older adolescents
Concentration: 2.5%, 4%, 5%, 10% Application/ml
Children ≥12 years: use 2.5–5% initially. Avoid near eyes, mouth, nasal mucosa. Avoid in children <12 unless under specialist guidance.

Dose adjustments

Renal

N/A — topical use.

Hepatic

N/A — topical use.

Clinical pearls

  • Only topical acne agent that is bactericidal (not bacteriostatic) — C. acnes cannot develop resistance to oxidative mechanism
  • Critical for antibiotic resistance prevention — BAD guidelines strongly recommend combining BPO with any topical or oral antibiotic
  • Bleaching warning: warn patients about fabric bleaching — white towels and old pillowcases essential; avoid coloured clothing
  • Start at 2.5% to minimise irritation; 5% is equally effective in most patients with less irritation than 10%
  • Duac gel (BPO + clindamycin): convenient once-daily combination with enhanced efficacy

Contraindications

  • Hypersensitivity to benzoyl peroxide
  • Application near eyes, mouth, or mucous membranes

Side effects

  • Local skin dryness and peeling (very common — dose-dependent)
  • Erythema and irritation
  • Bleaching of hair, clothing, and bedding (peroxide effect — advise white pillowcase)
  • Contact dermatitis (sensitisation — rare)

Interactions

  • Topical retinoids (adapalene, tretinoin) — can inactivate each other if used simultaneously; use at different times of day (BPO in AM, retinoid in PM)
  • Concurrent topical antibiotics — BPO actively reduces antibiotic resistance when combined (beneficial interaction)

Monitoring

  • Skin tolerance (dryness, irritation)
  • Acne response at 6–8 weeks
  • Contact sensitisation (rare)

Reference: BNFc; BNF; BAD Acne Guidelines 2021; NICE CG184. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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