Nitrofurantoin disposition

Abstract

The antibiotic nitrofurantoin (50 mg) was administered in a 3-way random crossover design to 6 healthy men. After a 45 min i.v. infusion the plasma concentration data could be described by a 2-compartment open-body model with a terminal t1/2 [half-life] of 58.1 .+-. 15 min. Oral availability of a tablet was 0.87 .+-. 0.13 on a fasting stomach and 0.94 .+-. 0.13 when taken with food. Absorption appeared to be complete, the absorption rate profile was complex and erratic. Two subjects failed to achieve the minimum effective urine concentration of 32 .mu.g/ml. After the i.v. infusion 47 .+-. 13% of the dose was excreted unchanged in the urine and 1.2 .+-. 0.3% was recovered as the reduced metabolite aminofurantoin.