 Prodrugs that release pivalic acid when broken down by the body—such as pivampicillin, pivmecillinam, and cefditoren pivoxil—have long been known to deplete levels of carnitine.This effect is not due to the drug itself but to pivalate, which is mostly removed from the body by forming a conjugate with carnitine.Although short-term use of these drugs can cause a marked decrease in blood levels of carnitine, it is unlikely to be of clinical significance; long-term use, however, is not recommended.