Rasmussen et al. (in J Inherit Metab Dis. 2012 May 8. Epub) recently published a series of patients with primary carnitine deficiency who hadÂ exposure to antibiotics containing pivalic acidÂ and developed encephalopathy andÂ lethal cardiac arrhythmia. Certian formulations of common antibiotics, such as ampicillin, contain pivalic acid in their prodrug form, and primary carnitine deficiency should be in the differential diagnosis for patients receiving these antibiotics who have a mental status change/hepatoencephalopathy. However, recognizing which antibiotic forms contain pivalic acid is not always obvious at first glance. Our in-hospital pharmacy was unable to tell me how frequently these prodrug formulations areÂ dispensed as compared to non-pivalic acid containing formulations.
Hilary Vernon, MD PhD