This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may process the narcotic pain medicine more slowly.
What might happen:
The effects of your pain medicine may increase and cause increased drowsiness, slowed breathing, and a decrease in blood pressure.
What you should do about this interaction:
If you experience excessive drowsiness, slowed breathing, weakness, fatigue, or dizziness, contact your doctor. It may be necessary to monitor your blood pressure and breathing rate. Your doctor may need to adjust the dose of your pain medicine.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Swett C Jr, Cole JO, Hartz SC, Shapiro S, Slone D. Hypotension due to chlorpromazine. Relation to cigarette smoking, blood pressure, and dosage. Arch Gen Psychiatry 1977 Jun;34(6):661-3.
2.Stambaugh JE Jr, Wainer IW. Drug interaction: meperidine and chlorpromazine, a toxic combination. J Clin Pharmacol 1981 Apr; 21(4):140-6.
3.Sadove MS, Levin MJ, Rose RF, Schwartz L. Chlorpromazine and narcotics in the management of pain of malignant lesions. J Am Med Assoc 1954 Jun 12; 155(7):626-8.
4.Jackson GL, Smith DA. Analgesic properties of mixtures of chlorpromazine with morphine and meperidine. Ann Intern Med 1956 Oct;45(4):640-51.
5.Dundee JW. Chlorpromazine as an adjuvant in the relief of chronic pain. Br J Anaesth 1957;19:28-34.
6.Lambertsen CJ, Wendel H, Longenhagen JB. The separate and combined respiratory effects of chlorpromazine and meperidine in normal men controlled at 46 MM Hg alveolar PCO2. J Pharmacol Exp Ther 1961; 131:281-93.
7.Hoffman JC, Smith TC. The respiratory effects of meperidine and propiomazine in man. Anesthesiology 1970 Apr;32(4):325-31.
8.Steen SN, Yates M. The effects of benzquinamide and prochlorperazine, separately and combined, on the human respiratory center. Anesthesiology 1972 May;36(5):519-20.
9.Keeri-Szanto M. The mode of action of promethazine in potentiating narcotic drugs. Br J Anaesth 1974 Dec;46(12):918-24.
10.Reier CE, Johnstone RE. Respiratory depression: narcotic versus narcotic-tranquilizer combinations. Anesth Analg 1970 Jan-Feb; 49(1):119-24.
11.McGee JL, Alexander MR. Phenothiazine analgesia--fact or fantasy?. Am J Hosp Pharm 1979 May;36(5):633-40.