Rifampicin 300–600mg BD

How it works

It inhibits bacterial DNA-dependent RNA polymerase, suppressing RNA synthesis, and has good penetration into bone and biofilm.

Prescribing in practice

• It is a potent inducer of hepatic cytochrome P450 enzymes and causes numerous clinically important interactions, including reduced efficacy of warfarin, combined hormonal contraceptives and many other drugs.
• It must never be used as monotherapy for active infection because resistance emerges rapidly; it is always combined with another active agent.
• It can cause hepatotoxicity and commonly produces orange-red discolouration of urine, tears and other body fluids.

Monitoring

Monitor liver function and full blood count during therapy, and review concurrent medicines for induction-related interactions.

Counselling the patient

• Your urine, sweat and tears may turn an orange-red colour, which is harmless but can stain soft contact lenses.
• Use an additional non-hormonal method of contraception, as this medicine reduces the effectiveness of the contraceptive pill.
• Report yellowing of the skin or eyes, nausea or unusual tiredness as these may indicate liver problems.

Evidence & guidelines

Guidelines for prosthetic joint infection support rifampicin combination therapy for staphylococcal biofilm-associated infection.