Tetracycline and minocycline treatment.

The effect of 1,000 mg of tetracycline hydrochloride and 200 mg of minocycline hydrochloride on Propionibacterium acnes levels and skin-surface lipid levels was measured in 15 patients with acne. Minocycline produced a significantly greater reduction in the P acnes counts that persisted even up to three weeks after discontinuation of the minocycline therapy, in contrast to the return of P acnes to baseline counts within three weeks after discontinuation of tetracycline therapy. A similar persistence of effect for reduction of skin-surface free fatty acid levels and clinical lesions was also seen with minocycline therapy.