# Characteristics of and treatment outcomes in rifampicin-intolerant patients

## TL;DR

This study finds that older patients and those with diabetes are more likely to be intolerant to rifampicin, a key TB drug, but treatment outcomes remain similar.

## Contribution

The study identifies demographic and clinical factors associated with rifampicin intolerance and evaluates the effectiveness of rifabutin as an alternative.

## Key findings

- Rifampicin intolerance was more common in older patients, females, and those with diabetes.
- Rifabutin was successfully used in 70% of patients intolerant to rifampicin.
- Treatment duration was longer for rifampicin-intolerant patients, but outcomes were similar.

## Abstract

Rifampicin (RIF) is considered the backbone of TB treatment, but adverse effects often limit its use.

This retrospective cohort study examined patients treated for TB disease at our institution, and compared those who received RIF to those who were intolerant to RIF.

A total of 829 patients were included. Seventy-six patients (9%) were intolerant to RIF. Patients with RIF intolerance were significantly older (median age: 67 years, IQR 50–78 vs. 48 years, IQR 31–70; P < 0.0001), and were more likely to be female (57% vs. 41%; P = 0.01) and have concurrent diabetes mellitus (37.3% vs. 19%; P < 0.0001) compared to those who tolerated RIF. RIF intolerance was most commonly due to transaminitis (25%), cytopenia (14.5%), rash (17.1%) and gastro-intestinal intolerance (7.8%). Twenty patients were subsequently challenged with rifabutin, and this was successful in 70%. The mean treatment duration was significantly longer in patients who were intolerant to RIF (335 vs. 270 days; P < 0.001). There was no significant difference in treatment outcomes.

RIF intolerance is more common in older patients, females, and those with concurrent diabetes mellitus. Patients who could not tolerate RIF had a longer duration of therapy, but no difference in treatment outcomes. When attempted, rifabutin was well tolerated in most patients with a previous RIF-related adverse event.