Venous thrombosis and rifampicin.

In a retrospective analysis of clinically diagnosed and lower limb deep vein thrombosis (DVT) proven by contrast venography, DVT complicated admissions in 46 (3.4%) of 1366 adult patients treated in a tuberculosis hospital during 1986. Analysis of 7542 admissions during 1978-86 showed a relative risk of 4.74 in patients treated with regimens including rifampicin compared with other regimens. DVT was significantly more common in winter months and usually occurred within 2 weeks of treatment being started. This probable association between rifampicin and DVT does not contraindicate use of this drug, but measures to prevent DVT should be taken in inpatients receiving rifampicin.