September 14: 10.20 a. m., 20 cc 2 per cent caffein (0.124 gram per kilo) injected into the back; 11 a. m., tetanus and death. Autopsy: Lungs congested; liver congested and showed hemorrhagic spots in capsules and fatty degeneration; kidneys slightly congested; other organs normal.
Cat 48. Black female. Weight, 3,050 grams.
September 14: 18 cc 2 per cent caffein (0.118 gram per kilo) injected subcutaneously in the back; 10.30 a. m., violent convulsions and death. Autopsy: Lungs congested in spots showing numerous petechia; liver congested; spleen congested; other organs normal.
The diminished resistance to caffein of cats Nos. 43 and 48 might be due to the pathologic changes found on autopsy, for evidence is not wanting that the toxicity of drugs might be greatly altered under pathological conditions. Hunt[40] has shown that resistance to acetonitril is considerably diminished in chronic alcoholism. This seems to be true also of other drugs under abnormal conditions. Smaller doses of atropin[78] are required in lead poisoning than under normal conditions to produce the same results. The following experiment is of interest in this connection, for in this case a much smaller dose than was given in experiments Nos. 43 and 48 produced the typical symptoms of caffein poisoning and proved to be fatal.
Cat 47, black and white male. Weight, 4,220 grams.
September 15: Received subcutaneously 18 cc 2 per cent caffein (0.084 gram per kilo); no symptoms observed for about six hours.
September 16: No symptoms.
September 17: Weight, 4,250 grams; injected 18 cc 2 per cent caffein (0.084 gram per kilo); tetanus and death after two hours. Autopsy: Severe hemorrhagic pneumonia; kidneys pale, other organs normal.
Since two controls survived the same dose in proportion to the body weight of the animal without showing any symptoms, the assumption is justified that the lower resistance to caffein was due to the presence of pneumonia, thus affording additional support to the view that the toxicity of caffein may be increased in disease.