NOTE: PQ, prequalified; SRA, stringent regulatory authority.
SOURCE: Hedman, 2012. Presentation at IOM workshop on Developing and Strengthening the Global Supply Chain for Second-Line Drugs for Multidrug-Resistant Tuberculosis.
1 percent failed due to extreme deviations.4 Hedman suggested that the general scarcity of data linking patient outcomes to QA status of a particular product has inhibited the ability to derive accurate conclusions about the true risk of treatment with non-QA drugs or substandard drugs.5 She therefore noted that there is a need to mine in-country primary data from MDR TB programs to inform the market and guide SCM. Joël Keravec, Brazil Country Program Director, MSH, commented that it is particularly difficult to link SLDs with treatment outcomes because MDR TB treatment regimens comprise multiple drugs and it is not possible to isolate the impact of one drug from another. A similar problem arises because patients are treated with drugs coming from different batches throughout the course of their lengthy treatment.
4 WHO Survey of Quality of Anti-TB Medicines in Selected Newly Independent States of the Former Soviet Union; none of the samples were assumed to be counterfeit. Extreme deviation was defined as the content of API deviating by more than 20 percent from the declared content and/or the average dissolution of tested units lower than 25 percent below pharmacopoeia Q value.
5 It would be unethical to systematically compare, or randomize in the context of a study, patients using substandard versus QA drugs.