Topical Antibiotic/Antiprotozoal — Rosacea Pregnancy: Use with caution — topical use generally considered acceptable; prefer azelaic acid in pregnancy (better safety data)

Metronidazole Topical

Brand names: Rozex, Metrogel, Metrosa

Adult dose

Dose: 0.75% gel or cream — apply a thin layer to affected areas

Route: Topical

Frequency: Twice daily (morning and evening after cleansing)

Max: Twice daily application

First-line topical treatment for papulopustular rosacea (subtype 2). Reduces inflammatory papules and pustules. Effect seen from 4–8 weeks. Long-term maintenance treatment. 1% formulation for once-daily application available (Rozex 1%).

Paediatric dose

Dose: Not applicable (rosacea is predominantly adult) topical/kg

Route: Topical

Frequency: Twice daily

Max: Twice daily

Not routinely used in children — rosacea is rare in paediatric population; specialist use only if perioral dermatitis suspected

Dose adjustments

Renal

No dose adjustment required (topical — negligible systemic absorption)

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Not routinely used in children — rosacea is rare in paediatric population; specialist use only if perioral dermatitis suspected

Clinical pearls

Rosacea subtypes: erythematotelangiectatic (subtype 1), papulopustular (subtype 2 — best response to metronidazole), phymatous (subtype 3 — rhinophyma), ocular (subtype 4)
Reduces inflammatory papules and pustules by anti-inflammatory and antiprotozoal (Demodex) mechanisms — not primarily antibacterial in rosacea
Triggers to avoid in rosacea: UV exposure, hot drinks, alcohol, spicy food, extremes of temperature, stress — lifestyle modification equally important
Alternative topicals: azelaic acid 15% (Finacea), ivermectin 1% cream (Soolantra) — ivermectin superior to metronidazole in head-to-head trials (ATTRACT study)
Facial flushing/erythema: brimonidine gel (Mirvaso) or oxymetazoline 1% cream — alpha-agonists causing vasoconstriction; separate from anti-papulopustular treatment
Oral doxycycline 40 mg modified-release (Efracea) is first-line systemic for moderate-severe papulopustular rosacea — anti-inflammatory dose

Contraindications

Hypersensitivity to metronidazole or nitroimidazoles

Side effects

Local skin irritation (stinging, burning — transient)
Dryness
Erythema worsening (transient)
Contact dermatitis (rare)
Metallic taste (rare — systemic absorption negligible but occasionally reported)

Interactions

Negligible at topical doses — no clinically significant systemic interactions

Monitoring

IGA score (Investigator Global Assessment) — papule/pustule count
Skin tolerability

Reference: BNFc; BNF 90; BAD Rosacea Guidelines 2017; ATTRACT Trial (Taieb et al. Br J Dermatol 2015); NICE CKS Rosacea. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways