Minocycline.

Minocycline has proved to have a wider spectrum of activity against both aerobic and anaerobic bacteria and has enhanced tissue penetration when compared with its tetracycline congeners. The latter, and possibly the former, can be related to its increased lipophilicity in the physiologic pH range. It appears to be a superior chemoprophylactic agent against sulfonamide-resistant meningococci that do not become minocycline resistant as a result of treatment. The clinical promise of this agent has been dimmed, however, by recent reports of vestibular toxicity manifest in ambulatory patients. Though data on the frequency and severity of these symptoms are in some conflict, minocycline cannot currently be recommended for general clinical use.