Acne and Rosacea Charity Training Manual

Systemic antibiotics
Tetracyclines
The tetracyclines are generally reported to be the most effective treatment for rosacea. It should be noted, that tetracyclines, as with all systemic
antibiotics, have their main effect in inflammatory lesions of rosacea and have little or no effect on flushing and redness. As bacteria are not implicated in
the pathogenesis of rosacea, the main effect of the tetracyclines is their potent anti-inflammatory effect. Oxytetracycline at 250-500mg BD would be a
suitable dose.
Doxycycline, at 100mg OD is a popular choice in rosacea as it is frequently used in ocular rosacea. Always warn
patients to take this drug with food, as the capsule of the antibiotic can adhere to the oesophagus causing a
chemical burn. It can also cause significant photosensitivity.
A low dose, slow release doxycycline (40mg/day marketed as Efracea) has been developed for the treatment of
inflammatory rosacea. The blood levels with this preparation never reach antibiotic levels, so should have no effect
on the gastrointestinal tract and should not induce vagina candidiasis.
Trimethoprim
Trimethoprim is a good second line antibiotic for the treatment of inflammatory rosacea. It can be prescribed at 200-300mg BD. It is generally well
tolerated but there is a low incidence of allergic reaction to the drug, with the development of a widespread itchy rash after 10 days of taking the drug. If
this happens, the drug should be stopped and the rash will settle after a few days. If itching is severe it can be treated with a mild topical steroid or
calamine lotion.
Oral metronidazole
Oral metronidazole – dose 200mg TDS, is very effective in severe inflammatory rosacea not responding to other antibiotics. Patients should be advised to
avoid alcohol while taking this antibiotic as it can have an Antabuse effect.
Glossary
• Antabuse – a drug used to treat alcoholism – it leads to alcohol being converted into formaldehyde which causes severe vomiting