USA – FDA addresses nitrosamines in TB drugs

Nitrosamine impurities have now been found in two tuberculosis drugs, prompting the US Food and Drug Administration (FDA) to clarify how it will handle elevated levels of the potential carcinogen in life-saving antibiotics.

Both rifampin and rifapentine are antibiotics used to treat tuberculosis, and rifampin is also used to treat other serious bacterial infections. Elevated levels of nitrosamines have been found in samples of both substances: the nitrosamine 1-methyl-4-nitrosopiperazine (MNP) was found above the acceptable intake limit of 0.16 parts per million (PPM) in rifampin. Rifapentin samples had another nitrosamine, 1-cyclopentyl-4-nitrosopiperazine (CPNP), at levels above that substance’s acceptable intake limit of 0.1 ppm…