Background:

The true frequency of adverse reactions (AR) attributed to antituberculosis drugs its unknown since they are seldom notified and therefore not reported.

Material and methods:

retrospective analysis of the files of the Tuberculosis Clinic at the Hospital General Tijuana to determine the frequency of AR in patients treated with a combination of first and second line antituberculosis drugs.

Results:

The most frequent AR to antituberculosis drugs were: renal dysfunction (75.9%), hepatitis (82.8%), hematologic abnormalities (79.3%), digestive AR (40%), hearing loss (26.7%), vestibular symptoms (15%) and tendinopathy (30%).

Conclusions:

AR to antituberculosis drugs are common and contribute to noncompliance. They must be routinely monitored and deal with, either with ancillary drugs, drug schedule modification and if needed with cessation of the offending drug.