Effect of three antibacterial drugs in lowering blood & stool ammonia production in hepatic encephalopathy

Neomycin (700 mg/8 h), ampicillin (500/6 h) and metronidazole (400 mg/8 h), were compared for their effect, on oral administration for 4 days, in reducing blood ammonia in 27 patients with stable chronic liver disease. It was found that there was 38.2, 38.5 and 8.7 m mol/litre mean reduction in blood ammonia in the neomycin, ampicillin and metronidazole treated groups respectively. The difference in blood ammonia was statistically significant for both neomycin (P=0.01) and ampicillin (P=0.03) but there was no significant change after metronidazole treatment (P=0.6). The total stool enzyme activity at optimum pH was maximally reduced by ampicillin and minimally with metronidazole