THE VASOCONSTRICTOR AND PRESSOR EFFECTS OF ORCIPRENALINE, MEDIATED BY ITS ALPHA-ADRENERGIC ACTION, MAY BE ENHANCED BY THE CONCOMITANT ADMINISTRATION OF DRUGS WITH SIMILAR EFFECTS, SUCH AS ERGOT ALKALOIDS OR OXYTOCIN. SEVERE HYPERTENSION MAY ALSO DEVELOP IF ORCIPRENALINE IS GIVEN WITH A BETA BLOCKER SINCE THE BETA BLOCKER OPPOSES THE BETA ADRENERGIC ACTION OF ORCIPRENALINE. ADMINISTRATION OF ORCIPRENALINE OR NORADRENALINE WITH TRICYCLIC. ANTIDEPRESSANTS CARRIES A RISK OF INDUCING HYPERTENSION AND ARRHYTHMIAS. THE ACTION OF ORCIPRENALINE OR NORADRENALINE MAY BE ONLY SLIGHTLY ENHANCED BY AN MAOIS. THE HYPOKALAEMIC EFFECT OF ORCIPRENALINE MAY BE POTENTIATED BY OTHER DRUGS THAT CAUSE POTASSIUM LOSS, INCLUDING CORTICOSTEROIDS, POTASSIUM-DEPLETING DIURETIC. INTERACTIONS ARE SIMILAR TO SALBUTAMOL : CONCOMITANT ADMINISTRATION OF OTHER B-2 AGONISTS WITH CORTICOSTEROIDS, DIURETICS OR XANTHINES INCREASE THE RISK OF HYPOKALEMIA. TRICYCLIC ANTIDEPRESSANTS INCREASE THE PRESSOR EFFECT OF SYMPATHOMIMETICS. MUSCLE RELAXANTS. SALBUTAMOL GIVEN INTRAVENOUSLY HAS BEEN REPORTED TO ENHANCE THE NEUROMUSCULAR BLOCKADE PRODUCED BY PANCURONIUM AND BY VECURONIUM. SYMPATHOMIMETICS. PATIENTS RECEIVING SALMETEROL MAY REQUIRE SALBUTAMOL TO CONTROL AN ACUTE ATTACK OF BRONCHOSPASM.
ONE STUDY INDICATED THAT THE EFFECTS MIGHT BE ADDITIVE, BUT ANOTHER DEMONSTRATED THAT PATIENTS RECEIVING SALMETEROL HAD REDUCED SENSITIVITY TO SALBUTAMOL AND MIGHT NEED HIGHER DOSES OF THE LATTER FOR ACUTE RELIEF. SERUM DIGOXIN LEVELS ARE DECREASED BUT THERE MATY BE CHANCES OF DIGOXIN TOXICITY BECAUSE OF HYPOKALEMIA CAUSED BY SALBUTAMOL.