Tretinoin with erythromycin

How it works

Tretinoin normalises follicular keratinocyte turnover to clear and prevent comedones, while erythromycin reduces Cutibacterium acnes colonisation and the associated inflammatory response; the retinoid helps reduce the risk of antibiotic resistance.

Prescribing in practice

• The retinoid component makes it contraindicated in pregnancy, and women of child-bearing potential should use effective contraception.
• Topical antibiotic therapy should be time-limited and is best paired with benzoyl peroxide rather than used alone, to reduce the risk of antimicrobial resistance.
• Local irritation, dryness, peeling and increased photosensitivity are common, so advise sun protection and avoid application to broken or inflamed skin.

Monitoring

No laboratory monitoring is required; review the acne response and skin tolerance and avoid prolonged courses of the antibiotic component.

Counselling the patient

• Apply a thin layer across the whole affected area at night and protect the skin from the sun during the day.
• Mild dryness and irritation usually settle; allow several weeks to see benefit.
• Avoid in pregnancy or when trying to conceive.

Evidence & guidelines

Fixed combinations of a topical retinoid with a topical antibiotic are recommended by NICE for acne, with antibiotic duration minimised to limit resistance.