Propionylcarnitine (PC) excretion has been measured during a clinical trial of metronidazole therapy in two patients with propionic acidaemia and two patients with methylmalonic aciduria. All patients were in good metabolic control and were receiving L-carnitine. While total propionate excretion was reduced by up to 40% in all four patients during metronidazole therapy, the excretion of propionylcarnitine remained largely unchanged. PC comprised up to 80% of total propionate excretion in patients with propionic acidaemia. Conclusion. These results suggest an extra-hepatic source and/or differing compartmentation for PC formation from those for the production of other metabolites of propionyl-CoA.
Burns, S. P., Iles, R. A., Saudubray, J. M., & Chalmers, R. A. (1996). Propionylcarnitine excretion is not affected by metronidazole administration to patients with disorders of propionate metabolism. European Journal of Pediatrics, 155(1), 31-35. https://doi.org/10.1007/BF02115623