Parenteral toxicity studies with benzyl alcohol

Abstract

Benzyl alcohol was injected into mice, rats, dogs, and monkeys and compared with ethyl alcohol to delineate its limits of tolerance. Intravenously, 1 ml/kg of 0.9% benzyl alcohol did not affect, in anesthetized and unanesthetized dogs and anesthetized monkeys, the blood pressure, heart rate, respiration, ECG or hematalogic parameters. The lethal iv dose of 0.9% benzyl alcohol in anesthetized, normovolemic dogs was 88–113 ml/kg (0.83–1.06 g/kg). Intracarotid and intrarenal injections of 0.9% benzyl alcohol did not cause any significant effects on ECG, blood pressure, heart rate, respiration or EEG of anesthetized dogs. Rapid iv injections of 0.9% benzyl alcohol were nonlethal in mice at 50 ml/kg (0.48 g/kg). Both 0.9% benzyl and ethyl alcohol could be given, iv, to rats, slowly, with no fatalities at 40 ml/kg. After rapid injection, the LD50 for 0.9% benzyl was 33.4 ml/kg while 37.5 ml/kg of the ethyl alcohol was nonlethal. Volumes of 22.5 ml/kg or less of 0.9% benzyl alcohol were nonlethal in rats. There is a calculated safety factor of 38 following a rapid injection of a 30-ml vial dose of 0.9% benzyl alcohol to a 50-kg adult. Intraarterially, 0.9% benzyl and ethyl alcohol were tolerated by rats at 44.5 ml/kg. Benzyl alcohol (94%) was 23 times more toxic in rats, iv, than ethyl alcohol (95%). Again, the calculated LD50 in mice for benzyl alcohol (94%) was less than 0.5 ml/kg (0.48 g/kg), and that for ethyl alcohol (95%) was 1.9 ml/kg (1.46 g/kg).