Severe hypertension has been reported when Oxytocin was given 3 to 4 hours following prophylactic administration of a vasoconstrictor in conjunction with a caudal block anesthetic. Cyclopropane anesthesia may modify Oxytocin's cardiovascular effects, so as to produce unexpected results such as hypotension. Maternal sinus bradycardia with abnormal atrioventricular rhythms have also been noted when Oxytocin was concomitantly administered with cyclopropane anesthesia.