Clinical Pharmacological Studies with Bacampicillin

Abstract

Ampicillin is a widely used semisynthetic penicillin with a high activity in vitro against Gram-positive and Gram-negative bacteria. A disadvantage, however, is its incomplete oral absorption, 30–50% of the drug being excreted unchanged in the urine (Rolinson et Sutherland 1973). In attempts to improve absorption, derivatives which are hydrolysed to ampicillin in vivo have been made. Metampicillin and hetacillin, condensation products of ampicillin with formaldehyde and acetone respectively, were reported to give superior blood levels of ampicillin (Franchi et Perraro 1967; Bunn et al. 1966) but this has later been questioned (Sutherland et al. 1972; Sutherland et Robinson 1967). Certain ampicillin esters, such as pivampicillin and talampicillin, are orally well absorbed giving serum levels of ampicillin higher than those obtained with ampicillin itself (Daehne et al. 1970; Clayton et al. 1974; Shiobara et al. 1974). In comparative trials between ampicillin and pivampicillin upper gastrointestinal discomfort appears to be more troublesome while the frequency of diarrhoea seems to be less pronounced with pivampicillin (Wilcox et al. 1973). Preliminary reports from Japan on talampicillin indicate a higher frequency of upper gastrointestinal side effects than normally seen with ampicillin (Gomi et al. 1975).