Effect of short-term treatment with pivalic acid containing antibiotics on serum carnitine concentration--a risk irrespective of age.

Treatment with pivalic acid containing prodrugs has been shown to cause carnitine depletion by loss of pivaloyl carnitine in urine. A 7-day standard pivmecillinam treatment of adults lead to a marked decrease of the free serum carnitine concentration (44.6 to 12.9 mumol/liter), whereas no change was seen in those given norfloxacine (40.0 to 40.5 mumol/liter). In some patients irrespective of age the free serum carnitine concentration was decreased to levels (around 10 mumol/liter) at which an impaired ketone-body production may occur. Therefore, there is reason for cautious use of this type of drug irrespective of the age of the patients.