PHARMACOKINETICS OF ANTIINFECTIVE AGENTS IN PEDIATRIC-PATIENTS

Various differences in drug disposition exist between children and adu lts. For example, the volume of distribution (Vd) for many drugs is la rger in children than in adults. Other parameters, including excretion and elimination may be altered in children compared with adults. The penicillins and cephalosporins are used commonly for the treatment of infection in paediatric patients. The increased Vd in children contrib utes to the increased elimination half-life of these agents. Clearance of the acylureido-penicillins is increased in children with cystic fi brosis, a disease that decreases the elimination half-life for these d rugs. Aminoglycosides distribute into extracellular fluid and their ph armacokinetic profile is affected by changes in Vd. The Vd for aminogl ycosides is slightly higher in children than in adults. Children with cystic fibrosis, burns, or cancer have higher clearance rates and larg er Vd values for aminoglycosides. Few data in the literature address t he pharmacokinetics of other anti-infective agents, including vancomyc in, teicoplanin, erythromycin, metronidazole, chloramphenicol, and cot rimoxazole (trimethoprim-sulfamethoxazole), in children. Similarly, th ere is little information regarding the pharmacokinetic profile of ant ivirals and antifungals in children. Dosage guidelines are available t o enable the clinician to initiate anti-infective therapy in children. Subsequent dosage requirements may change based on the patient's curr ent clinical condition. Although several studies have investigated the pharmacokinetics of anti-infectives in neonates and adults, data for children are Limited. Therefore, further studies are required so that the ever growing arsenal of anti-infectives can be administered approp riately to children.