Sulbenicillin: pharmacokinetics and penetration into bronchial secretion in elderly patients

This study evaluates the pharmacokinetics of sulbenicillin (alpha-sulfobenzylpenicillin) in elderly subjects after single and multiple doses and the penetration into bronchial secretion in elderly patients with chronically superinfected bronchial pathology. Peak plasma levels were 53.34 micrograms/ml (group I); 55.80 and 57.82 micrograms/ml (group II) after 1 h. The half-life (t 1/2 beta) was 1.47 h (group I); 1.49 and 1.62 h (group II). Renal clearance was 6.68 l/h; 6.25 and 5.44 l/h; whereas the volume of distribution was 18.02 l; 17.84 and 17.21 l for groups I and II respectively. The mean percentage of the recovered active drug in urine over 12 h was 77.72% of dose. The mean peak reaching the bronchial secretion was 3.60 micrograms/ml at the 4th hour. The results of the multiple dose study indicated that there was no apparent change in the distribution or elimination kinetics of sulbenicillin after 2 g i.m. administration. Thus, the kinetics from the multiple dose study were in close agreement with those from the single dose study and no accumulation of sulbenicillin was observed. This study provided satisfactory results and confirmed the significant presence of sulbenicillin into bronchial secretions.