Drug resistance in patients with tuberculous pleural effusions

To summarize data regarding categories, detection methods, prevalence and patterns of drug resistance among patients with tuberculous pleural effusion (TPE) and to comment on the management of suspected drug-resistant TPE.

Pleural and pulmonary tuberculosis (TB) present similar patterns of drug resistance. Approximately 10% and 6-10% of pleural Mycobacterium tuberculosis isolates are resistant to at least one first-line anti-TB drug or at least isoniazid, respectively. The prevalence of multidrug-resistant-pleural and extensively drug-resistant-pleural TB is 1-3% and 0-1%, respectively.

Although guidelines suggest the empirical standard anti-TB regimen (i.e. 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol followed by 4 months of isoniazid and rifampicin) for TPE treatment, the data regarding drug resistance among TPE patients are limited. The few studies examining the issue report a notable drug resistance. In suspected drug-resistant TPE, every effort is warranted to isolate M. tuberculosis to perform drug susceptibility testing and provide guided therapy. For this purpose, the use of cultures or molecular methods with pleural biopsies is superior to their use in pleural fluid. If still M. tuberculosis cannot be detected, prolonged administration of ethambutol with isoniazid and rifampicin during the continuation phase of treatment might be considered.