PREFERENTIAL ELIMINATION OF PIVALATE WITH SUPPLEMENTAL CARNITINE VIA FORMATION OF PIVALOYLCARNITINE IN MAN

1. To evaluate the effectiveness of carnitine administration in aiding the elimination of pivalate liberated from pivampicillin, studies wer e undertaken on seven paediatric patients treated for 7 days with comb ined pivampicillin and molar excess of carnitine. 2. A 22-fold increas e occurred in urinary carnitine ester excretion on the last day of tre atment (2967+/-604 versus 134+/-50 mumol/day, p<0.05); the pivaloylcar nitine was identified With C-13-n.m.r. Only pivalate was detected in t he urinary carnitine ester g.l.c. profile, the amount of this ester wa s equal to 92% of the daily pivalate intake. 3. The renal clearance ra te of carnitine esters significantly exceeded that of creatinine indic ating that the carnitine ester was eliminated by active transport. 4. The plasma concentration and urinary output of free carnitine were not changed significantly by the treatment, and the free and esterified c arnitine concentrations in red cells remained unchanged indicating tha t carnitine deficiency was prevented.