Metoclopramide/Promethazine Interactions

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:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Both of your medicines can cause abnormal muscle movements and a potentially life-threatening condition called neuroleptic malignant syndrome. Taking two medicines together that cause these effects can increase the risk of it happening to you.

What might happen:

You may develop uncontrollable muscle movements, including a condition called tardive dyskinesia. There is no cure for tardive dyskinesia, but symptoms may lessen or go away after you stop taking the medicines; however, the symptoms may be permanent.You may develop neuroleptic malignant syndrome, which may be life-threatening.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor or pharmacist) know right away that you are taking these medicines together. Contact your doctor right away if you develop any movements you cannot stop or control such as: new onset of uncontrollable muscle spasms (especially of the neck, shoulders or throat), new or worsening muscle tremors, lip smacking, chewing, puckering of the mouth, frowning or scowling, sticking out the tongue, blinking and moving the eyes, and shaking of the arms and/or legs. Contact your doctor right away if you develop any symptoms of neuroleptic malignant syndrome: high fever, stiff muscles, problems thinking, very fast or uneven heartbeat, and/or increased sweating.Your healthcare professionals 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.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.