Multidrug-resistant tuberculosis (MDR-TB) treatment in the UK: A study of injectable use and toxicity in practice

Background: Multidrug-resistant tuberculosis (MDR-TB) is an increasing challenge to health services globally. Although new drugs are in development, current guidelines still recommend prolonged use of injectable anti-microbials (usually amikacin, kanamycin or capreomycin). The evidence base to inform treatment and monitor-ing strategies is very limited. Methods: We conducted a retrospective study of patients initiating injectable antimicrobials for MDR-TB treat-ment in five UK centres between January 2004 and December 2009. (i) Current treatment and monitoring strategies were reviewed. (ii) The incidence of ototoxicity (defined both clinically and on audiological testing) and factors associated with ototoxicity were investigated using logistic regression. Results: (i) The choice of injectable antimicrobial varied. Of 50 MDR-TB patients, 29/50 (58%) received amikacin, 11/50 (22%) received capreomycin and 10/50 (20%) received streptomycin or a combination; reflecting a differ-ence in policy between centres. Only 21/50 (42%) patients received baseline screening by audiogram within 2 weeks of starting treatment and 16/50 (32%) then had monthly audiograms, with the majority screened mor