Serentil (mesoridazine) is a typical antipsychotic medication that belongs to a group of drugs called phenothiazines. This medication was developed to help control the symptoms of schizophrenia, but it will not cure the condition. Serentil may also be used to treat hyperactivity, restlessness, anxiety, and tension. Serentil works by blocking dopaminergic transmissions in the brain. 

As of 2012, Serentil is no longer available in the United States. If you live in the U.S. and are still taking this medication, you should speak with your healthcare provider about finding a suitable rep


  • How can I get the most out of my drug treatment with Serentil?
    In many cases where mental health treatment requires the use of psychotropic medication, psychotherapy may help a person achieve better, longer-lasting treatment outcomes. Medication is useful for many experiencing debilitating symptoms of mental health conditions, but does not address many of the underlying issues, behaviors, and emotions associated with mental health issues. If you are prescribed an antipsychotic medication, please consider contacting a qualified counselor or therapist to get the most out of your treatment.
  • What is the safest way to take this medication?
    Serentil comes in both tablet and liquid concentrate form; the concentrate should be diluted with a liquid such as water, orange juice, or grapefruit juice before being ingested. However, you should not dilute the concentrate with cola, coffee, or tea. The concentrate may cause irritation if it comes into contact with exposed skin. It is important to take this medication on a regular schedule, as directed by your doctor. Serentil is usually taken two to three times per day, preferably with food or milk to prevent an upset stomach. Because this drug builds up in your system gradually, it may take several weeks for you to experience its full therapeutic effect.
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    I forgot to take my medication. What should I do?
    If you miss a dose of this drug, take the missed dose as soon as you remember it. However, if you are close to your next scheduled dose, skip the missed dose completely and continue with your regular dosage schedule. If you take too much of this drug too quickly, it may lead to an overdose.
  • How do I know if I have overdosed on this drug?
    Check for signs and symptoms of overdose. These may include convulsions, high or low body temperature, agitation, erratic and uncontrollable movements, dizziness, deep sleep, irregular heartbeat, fainting, or coma.
  • What should I do if I have overdose on this drug?
    Seek emergency medical care or call a poison control center immediately.
  • What is the best way to store this medication?
    This drug should be kept tightly closed in the container it came in. Do not store this medication in locations exposed to excess heat, moisture, or light.

Considerations Before Use

This medication is no longer available by prescription in the U.S. Serentil may cause life-threatening, erratic heartbeats. This drug is not approved by the United States Food and Drug Administration (FDA) for treating elderly people who experience dementia, as it may increase the risk of death.

If you have been diagnosed with asthma, seizures, an overactive thyroid, irregular heartbeat, heart pain, glaucoma, asthma, emphysema, high or low blood pressure, bone marrow disease, Parkinson’s disease, kidney disease, urinary problems, liver disease, or lung problems, you should talk to your doctor before you begin to take this drug. Tell your doctor if you have ever been treated for alcoholism, depression, or if you have ever had shock therapy.

Serentil may interact with other medications, including antacids, antihistamines, sleep aids, pain relievers, weight loss aids, antidepressants, and heart medication. Check with your doctor or pharmacist before taking Serentil if you are currently taking other prescription drugs or supplements.

Safety Information

If you begin taking this medication, here are some important considerations for its use:

  • If you become pregnant while taking this medication, you should talk to your doctor about alternative treatments for your condition. This drug may cause problems in newborns if taken during pregnancy. Do not breastfeed if you are taking this medication as it is not known whether Serentil is able to pass into breast milk. Do not stop taking this medication unless you are told to do so by your doctor.
  • Wear protective clothing or use sun block if you need to spend a lot of time outside. This drug may make your skin more sensitive to sunlight.
  • This medication may cause drowsiness and dizziness. Do not engage in potentially hazardous activities such as driving, climbing, or operating heavy machinery until you find out how this medication affects you.
  • Avoid drinking alcoholic beverages while on this medication. Serentil may interact with alcohol and cause potentially dangerous levels of drowsiness, dizziness, or sedation.
  • You may experience dizziness if you quickly try to stand up after a prolonged period of sitting or lying down. Stand slowly, with both feet on the floor, in order to minimize falls. This condition is known as orthostatic or postural hypotension and is a common side effect of many psychotropic medications.
  • If you are having any type of surgery, including oral surgery, tell your surgeon or anesthesiologist that you are taking this drug.

Possible Side Effects

If you experience serious or severe side effects from Serentil, you should call your doctor. This drug may cause serious heartbeat irregularities. Contact your doctor right away if you have an unusually fast, pounding, or irregular heartbeat. Other serious side effects may include:

  • Muscle spasms in jaw, neck, or back
  • Rash
  • Yellowed eyes or skin
  • Eye pain or discoloration
  • Difficulty urinating or loss of bladder control
  • Frequent urination
  • Tremors or shakiness
  • Seizures
  • Dizziness, faintness, or lightheadedness
  • Pacing or restlessness
  • Unusual or uncontrollable movements of the tongue, face, mouth, or jaw, which may be linked to a condition known as tardive dyskinesia
  • Shuffling walk or slowed movements
  • Difficulty breathing

Less serious side effects may include:

  • Drowsiness
  • Upset stomach, vomiting, nausea, or diarrhea
  • Dry mouth and nasal congestion
  • Constipation
  • Anxiety or restlessness
  • Changes in appetite or weight gain
  • Increased skin sensitivity to sunlight
  • Loss of interest in sex
  • Menstrual irregularities


It is important to slowly taper off of this medication in order to avoid serious adverse reactions. Though it is not addictive, your body may have become accustomed to having this drug in its system. Possible symptoms of withdrawal include:

  • Nausea, stomach pain, or diarrhea
  • Dizziness or shakiness
  • The return of psychotic symptoms, including delusions or hallucinations


  1. (2004). Serentil. Retrieved from
  2. Medline Plus. (2009). Mesoridazine oral. Retrieved from

Page content reviewed by James Pendleton, ND.