Neomycin Absorption in Man

This study compares absorption of 2.0 g of neomycin sulfate administered orally and by enema and assesses the influence of intestinal ulceration on absorption of neomycin. Absorption after enema, as measured by urinary excretion of neomycin over 48 hours and by sequential serum neomycin concentrations, was similar to that seen after oral administration in normal subjects, patients with liver disease, and patients with upper gastrointestinal ulcerations. Increasing enema retention times did not increase neomycin absorption. Patients with active peptic ulcers or regional enteritis did not absorb excessive amounts of orally administered neomycin. Patients with active uncomplicated ulcerative colitis did not have enhanced absorption of rectally administered neomycin. In all groups of subjects studied, bacteriocidal urinary neomycin concentrations were encountered with surprising frequency. We conclude that enema-administered neomycin is absorbed to the same extent as that administered orally and that intestinal ulceration does not enhance neomycin absorption.