COMPARATIVE STUDY OF THE EFFECTS OF ORAL AND I.M. ATROPINE AND HYOSCINE IN VOLUNTEERS

The effects of equivalent doses of atropine and hyoscine following oral and i.m. administration were assessed on salivary secretion, heart rate, arterial pressure, body temperature, pupillary size, near-point of vision and sweat-gland activity. The ratio of oral to i.m. doses of atropine on heart rate and salivary secretion appears to be 2: 1 and that of hyoscine on salivary secretion about 5-6: 1. Follow-ing oral administration the effects on the eye are minimal even after the highest doses of the two drugs, while the decrease in salivation is adequate. The results of a recent countrywide survey (Mirakhur et al., 1978) have shown that more than 60 % of anaesthetists routinely give atropine or hyoscine in premedication, and that approximately the same number would prefer an oral anticholinergic drug if such were shown to be effective. Although many studies have compared atropine with other anti-sialogogue drugs (Galloon, 1956; Wyant and Dobkin, 1957; Wyant and Kao, 1974) few have compared th