MINOCYCLINE-INDUCED PIGMENTATION - INCIDENCE, PREVENTION AND MANAGEMENT

Pigmentation is a well recognised adverse effect of minocycline therap y. Various body sites, most notably the skin, nails, bones, thyroid, m outh and eyes are affected and the pigmentation may appear at multiple sites. In general, pigmentation results from long term administration of minocycline at cumulative doses greater than 100g, although cutane ous or oral mucosal pigmentation may appear, regardless of dose or dur ation of therapy. When the skin is involved, the blue-black pigmentati on develops most frequently on the shins, ankles and arms. Other patte rns of skin involvement include pigmentation that is either generalise d and symmetrical, or that develops at sites of inflammation. The bone s of the oral cavity are probably the most frequently affected sites o f pigmentation affecting greater than 20% of patients taking minocycli ne for more than 4 years. In contrast, the oral mucous membranes and t eeth are infrequently pigmented from minocycline. Ocular, thyroid and visceral pigmentation is also relatively uncommon and usually develops only with high doses and long term minocycline use. Whereas pigmentat ion of the skin and oral mucosa is generally reversible when the drug is discontinued, the pigmentation is often permanent when other sites are involved. Although minocycline-induced pigmentation is not harmful , the drug should be discontinued when the adverse effect is recognise d. All patients receiving minocycline, especially those treated for lo nger than 1 year, require screening for the development of pigmentatio n.