Isolated cases of contraceptive failure have been attributed to various
sulfonamides.
It is possible that the anecdotal cases of contraceptive failure with antibacterials are indistinguishable from the normal accepted failure rate and no special precautions are required. However, some specialists recommend that additional
contraceptives, such as condoms, should be used for short courses of antibacter- ials. For guidance on the use of antibacterials with
contraceptives, see contracep- tives.