The pharmacokinetics of sultamicillin

Sultamicillin is a mutual prodrug of ampicillin and sulbactam, a beta-lactamase inhibitor. When administered orally, sultamicillin is readily absorbed and rapidly hydrolyzed to provide high levels of its two constituents in the peripheral circulation. Peak serum concentrations of ampicillin are achieved that are approximately three and one-half times those obtained with an equivalent amount of oral ampicillin. Equimolar concentrations of sulbactam are also provided, with both ampicillin and sulbactam being widely distributed among various body fluids and tissues. The pharmacokinetic parameters of the two components are similar, both being eliminated primarily by renal excretion. Although the elimination half-lives of ampicillin and sulbactam are each approximately 1 hour, the high serum concentrations achieved coupled with their synergistic bactericidal activity permit twice-daily dosing.