Ergotoxine Excitement

Abstract

The attention of investigators has been so centered on the peripheral effects of ergotoxine that the central action of this drug has received scant notice. Most of the studies of ergotoxine have been conducted upon anesthetized animals. In these its depressant action upon the respiratory center has been repeatedly reported. There have been few references, however, to central stimulation. Barger and Dale, 1 after intramuscular injection of ergotoxine in cats, observed vomiting and “hyperexcitability”. They have recorded similar findings including fever in rabbits. Githens 2 considered this fever to be of central origin. Rothlin 3 found clonic and tonic convulsions 3 hours after large intravenous doses of ergotamine in rabbits. Koppanyi and Evans 4 reported vomiting and defecation of central origin in dogs and cats after the administration of small doses of ergotamine. Recent studies 5 in which ergotamine has been intramuscularly administered to unanesthetized animals in amounts sufficient to affect the sympathetic system make no mention of central action.

The observations here reported were made upon cats. Unanesthetized animals were tied to boards. No injection was made until the subjects had been calmed. Ergotoxine ethanesulphonate (1 mg./kilo)∗ was administered by intracardiac injection. This procedure can be accomplished without any excitement of the cat. The immediate manifestations of the action of the drug were those of sympathetic stimulation, wide dilation of the pupil and pilo-erection, especially in the tail. One minute after injection, the central effects became evident. The reflexes were hyperactive, the slightest touch causing a single spastic response in all voluntary muscles. More dramatic, however, were the emotional changes in the animal. The cats previously calm and unmindful of the injection, showed marked rage and apprehension. The slightest stimulation, visual, auditory or tactual, caused a savage hissing and snarling. Objects, brought near the head of the cat were ferociously attacked and bitten.