Rifabutin

How it works

It inhibits bacterial DNA-dependent RNA polymerase, thereby suppressing RNA synthesis and bacterial growth.

Prescribing in practice

• Rifabutin is a potent enzyme inducer with numerous clinically important drug interactions, including with antiretrovirals; review concomitant medicines carefully.
• It can cause uveitis, particularly at higher exposures or with interacting drugs that raise its levels.
• Like other rifamycins, it may cause a harmless orange-red discolouration of urine and other body fluids.

Monitoring

Monitor full blood count and liver function, and remain alert for visual symptoms suggesting uveitis.

Counselling the patient

• Your urine, tears and sweat may turn an orange-red colour, which is harmless and can stain soft contact lenses.
• Report any eye pain, redness or visual changes promptly.
• Tell any prescriber you take this medicine, as it interacts with many drugs.

Evidence & guidelines

Rifabutin is an established alternative to rifampicin where drug interactions are a concern, as reflected in UK tuberculosis and HIV guidance.