[Basic and clinical trials of aztreonam in the field of pediatrics]

Serum and urinary concentrations and recovery rates of aztreonam (SQ26,776, AZT), a newly developed antibiotic, were studied for a total of 20 pediatric cases by one-shot intravenous injections of 10, 20 and 40 mg/kg to 3, 4 and 3 cases, respectively, and by intravenous drip infusion of 10, 20 and 40 mg/kg to 3, 4 and 3 cases for 1 hour, respectively. Clinical and bacterial effects of AZT were studied by administering 76.7 mg/kg per day on average for a total of 36 cases of tonsillitis (6), pneumonia (13), otitis media and pneumonia complication (1), pleurisy (1), sinusitis (1) and UTI (14). The above daily dose was given t.i.d. (9 cases) or q.i.d. (27 cases), by intravenous drip infusion for 30 minutes for one t.i.d. case and by one-shot intravenous injection for 7 days for the remaining 35 cases. Also, side effect and laboratory values were examined for 43 cases including 7 dropouts. Serum concentration of AZT in 10 pediatric cases were measured by dosing 10, 20 and 40 mg/kg by one-shot intravenous injection to 3, 4 and 3 cases, respectively. In every dosage group, the serum concentrations were highest 5 minutes after the intravenous injection with average values of 91.0, 174.0 and 175.3 mcg/ml, respectively. Dose response was observed between 10 mg/kg dose group and 20, 40 mg/kg dose groups, but it was not between 20 mg/kg group and 40 mg/kg group. This was considered to be attributable to the individual case-fluctuations in the 2 groups and to a high concentration case of 240.0 mcg/ml in the 20 mg/kg group. Half-life of each dosage group was 1.55, 1.65 and 1.93 hours. Serum concentrations of AZT in 10 pediatric cases at the dosage level of 10, 20 and 40 mg/kg for 3, 4 and 3 cases, respectively, by 1 hour intravenous drip infusion were highest at the end of the administration with average values of 95.7, 126.0 and 170.7 mcg/ml, respectively. There was a dose response among the 3 groups and the half-life of them were 1.02, 1.41 and 2.48 hours, respectively. A longer half-life of the 3rd group with 40 mg/kg administration than the other 2 groups was due to 1 particular case of 4.44 hours with unknown cause of such an exceptional extension.(ABSTRACT TRUNCATED AT 400 WORDS)