Joan Clahsen

Concentrations of antimicrobial agents in middle ear fluid, saliva and tears.

Antibiotics concentrations in middle ear fluid (MEF), saliva and tears were measured in children with persistent middle ear effusions undergoing tympanostomy tube placement. In 31 children given cefaclor, specimens of serum, saliva and MEF were collected at 0.5, 1, 2, 3 or 5 h after a dose. Another group of 37 children were randomized to receive a single dose of penicillin V, amoxicillin, ampicillin, erythromycin estolate, erythromycin ethylsuccinate, trimethoprim-sulfamethoxazole or cefaclor. Concentrations of antibiotics in saliva and tears bore no consistent relationship to those in MEF. Mean concentrations of all drugs in MEF were several-fold greater than the usual minimal inhibitory concentrations (MIC) of pneumococci, but only with trimethoprim and cefaclor were they greater than in usual MICs for Haemophilus influenzae. Concentrations of antibiotics in MEF in persistent effusions were comparable to those previously reported in acute purulent effusions.

Clinical Pharmacology of Cefadroxil in Infants and Children

The pharmacokinetics of cefadroxil suspension were studied in 30 children, 13 months to 12 years of age (mean age, 5.7 years). Average peak concentrations in serum of 11 to 14 μg/ml and of 7 to 10 μg/ml after 15- and 10-mg/kg doses, respectively, were not substantially affected by the feeding status. The serum half-life values were 1.3 to 1.5 h. Cefadroxil was detected in saliva of all children 2 h after 15-mg/kg doses: the levels ranged from 0.17 to 2.6 μg/ml (mean, 0.46 μg/ml). The average concentrations in urine were 1,700 and 2,620 μg/ml at 0 to 2 and 2 to 4 h, respectively, after 15-mg/kg doses. In a randomized controlled study of 50 children with impetigo, cefadroxil was as effective as penicillin G in curing existing lesions and in preventing development of new lesions. Cefadroxil may be useful for therapy of mucocutaneous and urinary tract infections in infants and children.

Comparative pharmacokinetics of cyclacillin and amoxicillin in infants and children.

Concentrations of cyclacillin in serum over a 6-h period were similar in fasted and milk-fed infants who received 25-mg/kg doses of cyclacillin suspension. Measured by the concentration in serum after oral administration of 15-mg/kg doses, cyclacillin was absorbed more rapidly, reached larger concentrations, and was cleared more promptly than was amoxicillin.