Skip to content
My WebMD Sign In, Sign Up

morphine oral

Narcotics/Phenothiazines

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.

Medical warning:

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.

References:

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.

See 460 Reviews for this Drug. - OR -

Review this Treatment

Find a Drug:

by name or medical condition or shape/color (Pill Identifier)

(for example: aspirin)

(for example: diabetes)

Report Problems to the Food and Drug Administration
 
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Ask the pharmacist

Questions about medications? Get expert answers by video or live chat about allergies, pregnancy, sleep, and more.
See the Ask the Pharmacist event schedule.

Ask a Question

Popular Slideshows & Tools on WebMD

hands on abdomen
Can you catch one?
Woman sitting in front of UV lights
Is yours working?
woman using breath spray
What's causing yours?
womans hand on abdomen
Are you ready for baby?
MS Overview
Recognizing symptoms.
bowl of yogurt with heart shape
Eat for a healthy heart.
woman doing pushups
To help you get fit.
Colored x-ray of tooth decay
Know what to look for.
Woman sitting with child
Do you know the symptoms?
mosquito
Stings, bites, burns, and more.
Allentown, PA
Are you living in one?
Thyroid exam
See how much you know.

Women's Health Newsletter

Find out what women really need.

WebMD the app

Get trusted health information. Whenever. Wherever... with your iPhone, iPad or Android.

Find Out More

IMPORTANT: About This Section and Other User-Generated Content on WebMD

The opinions expressed in WebMD User-generated content areas like communities, reviews, ratings, or blogs are solely those of the User, who may or may not have medical or scientific training. These opinions do not represent the opinions of WebMD. User-generated content areas are not reviewed by a WebMD physician or any member of the WebMD editorial staff for accuracy, balance, objectivity, or any other reason except for compliance with our Terms and Conditions. Some of these opinions may contain information about treatment or uses of drug products that have not been approved by the U.S. Food and Drug Administration. WebMD does not endorse any specific product, service, or treatment.

Do not consider WebMD User-generated content as medical advice. Never delay or disregard seeking professional medical advice from your doctor or other qualified healthcare provider because of something you have read on WebMD. You should always speak with your doctor before you start, stop, or change any prescribed part of your care plan or treatment. WebMD understands that reading individual, real-life experiences can be a helpful resource but it is never a substitute for professional medical advice, diagnosis, or treatment from a qualified health care provider. If you think you may have a medical emergency, call your doctor or dial 911 immediately.