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Updated: Sep 22, 2025

A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
Rifampin Drug-Drug-Interaction Studies: Reflections on the Nitrosamine Impurities Issue
Aernout van Haarst1, Stephen Smith2, Clare Garvin2
1Celerion, Scientific Affairs, Belfast, UK.
Abstract:
Clinical development of new drugs may require dedicated drug-drug interaction (DDI) studies, such as to evaluate the effect of cytochrome P450 3A induction on the pharmacokinetics of investigational drugs. However, as a result of N-nitrosamine impurity findings in marketed rifampin formulations, the application of rifampin in DDI studies has been halted. This mini-review considers the root cause and impact of the nitrosamine impurity as well as alternative options for the continued conduct of DDIs.
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