THE ACUTE RECTAL TOXICITY OF ACETYLSALICYLIC ACID

Abstract

The LD₅₀ ± S.E. of acetylsalicylic acid administered rectally to male albino rats was found to be 0.79 ± 0.027 g/kg, which is significantly less than the oral LD₅₀. The minimal dose producing toxic symptoms was about 0.20 g/kg. The most significant toxic signs were ataxia, drowsiness, dyspnea, pallor, diarrhea, and anorexia. The immediate cause of death was respiratory failure preceded by coma or clonic convulsions. Loss in body weight, inhibition of food intake, and interval until death were dose-dependent. The drug caused diuresis and aciduria but no significant changes in colonic temperature, or in urinary glucose or protein. Death at 4 to 9 hours was associated with extensive capillary–venous congestion and at 24 hours and over with degenerative changes in the kidneys and liver. Congestive and hemorrhagic ulcers appeared in the pyloric stomach at 4 hours, reached a peak at 24 hours, and thereafter began to heal. Local reaction in the colon and cecum was limited to mild inflammation. Significant loss of weight and a gain in water level occurred in most organs.