Codeine hypotension

Abstract

An investigation has been carried out of the hypotensor action of codeine, produced by the least effective quantity of its pliosphate by means of interarterial injections of the external carotyd artery, the internal one, the thoracic aorta, immediately above the disphragm, the abdominal aorta, immediately before the bifurcation and coronary artery; intravenous injections in the external jugular and saphena vein and intracardiac ones in the right atiricie, right ventricle and left ventricle, all in chloralsed animals with opened thorax and artificial respiration. The minimum doses producing hypotension are: internal carotyd artery 0,062 mgr. per Kg., external ca­rotyd from 3 to 6 mgr. per Kg., thoracic aorta and coronary artery, 0,250 mgr. per Kg. The remaining, between 0,5 and 1 mgr. per Kg. For the injection in the carotyd artery there is admited, either a direct central action, or a reflex action with a starting zone in the wall of that vessel or its continuing vessels or anastomosis. In the abdominal aorta there is appreciated a sensitive zone of a rapid hypotensor response, the origin of which might be attributed either to the receivers of the aorta itself or to the great trunks which part from it.