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Mesoridazine Side Effects

For the Consumer

Applies to mesoridazine: injectable solution, oral concentrate, oral tablet

If you experience any of the following serious side effects, stop taking mesoridazine and seek emergency medical treatment:

  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);

  • uncontrollable movements of the mouth, tongue, cheeks, jaw, arms, or legs;

  • fever;

  • muscle rigidity;

  • muscle spasms of the face or neck;

  • sweating;

  • irregular pulse;

  • fast or irregular heartbeats.

  • severe restlessness or tremor;

  • severe drowsiness;

  • blurred vision;

  • dizziness or fainting; or

  • a rash.

Other, less serious side effects may be more likely to occur. Continue to take mesoridazine and talk to your doctor if you experience:

  • dry mouth or stuffy nose;

  • constipation;

  • mild restlessness, drowsiness, or tremor;

  • difficult urination or dark urine;

  • decreased sex drive;

  • increased appetite; or

  • menstrual irregularities or swollen breasts.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

For Healthcare Professionals

Applies to mesoridazine: injectable solution, oral concentrate, oral tablet


Drugs with the potential to prolong the QTc interval have been associated with torsades de pointes-type arrhythmias and sudden death.[Ref]

Cardiovascular side effects including hypotension and tachycardia have been reported. Mesoridazine has also been reported to prolong the QTc interval in a dose related manner.[Ref]

Nervous system

Central nervous system side effects including drowsiness, Parkinson's syndrome, dizziness, weakness, tremor, restlessness, ataxia, dystonia, rigidity, slurring, akathisia, and motoric reactions (opisthotonos) have been reported. Autonomic nervous system effects including dry mouth, nausea and vomiting, fainting, stuffy nose, photophobia, constipation, and blurred vision have also been reported.[Ref]

Adverse effects including rigidity and motoric effects tend to occur later in therapy.[Ref]


Genitourinary side effects including inhibition of ejaculation, impotence, enuresis, incontinence and priapism have been reported.[Ref]


Dermatologic side effects including itching, rash, hypertrophic papillae of the tongue, and angioneurotic edema have been reported.[Ref]


1. "Product Information. Serentil (mesoridazine)" Boehringer-Ingelheim, Ridgefield, CT.

2. Starck LC, Talley BJ, Brannan SK "Mesoridazine use and priapism [letter]." Am J Psychiatry 151 (1994): 946

3. Compton MT, Miller AH "Priapism associated with conventional and atypical antipsychotic medications: A review." J Clin Psychiatry 62 (2001): 362-6

Not all side effects for mesoridazine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.