Tetracyclines-how safe are they?

Tetracyclines have now been in use for nearly 40 years. They have found great favour with dermatologists, who prescribe some 10% of all those produced for human use in the United States,1 and courses of treatment may be for months or years. Long-term follow-up studies have generally been reassuring and suggest that tetracyclines are relatively safe even in high doses. The topic of safety has gradually become stale and has not been reviewed in a British dermatology journal since 1969.2 However, new problems with tetracyclines are still being reported regularly in the literature and we feel there is now a need for an update of the subject, which may help practising dermatologists to recognize these recently described side effects at an early stage. This review will mention some examples where a specific member of the tetracycline group of drugs has been responsible for a specific side effect; however, many of the side effects are common to all drugs within the group3 and cross sensitivity occurs.4 Mechanisms are only touched upon in order to restrict the length of the review.