Compro (Prochlorperazine) - Rectal


Compro should not be used in older adults (65 and older) with dementia- or delirium-related psychosis being treated with atypical antipsychotic drugs because of an increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia).

What Is Compro?

Compro (prochlorperazine) is a prescription rectal suppository administered into the rectum. It is used as an antiemetic medication to treat severe nausea and vomiting in adults. 

Compro reduces nausea and vomiting by blocking dopamine receptors in an area of the brain called the chemoreceptor trigger zone.

Compro is administered rectally. However, prochlorperazine is also available through other administration methods in oral and injectable formulations.

Drug Facts

Generic Name: Prochlorperazine

Brand Name(s): Compro, Compazine

Administration Route: Rectal

Drug Availability: Prescription

Therapeutic Classification: Antiemetic

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Prochlorperazine

Dosage Form(s): Suppository

What Is Compro Used For?

Compro rectal suppositories are used to treat severe nausea and vomiting in adults. It is usually dosed twice daily, 25 milligrams (mg) administered via rectal suppository every 12 hours.

Compro comes as a rectal suppository for adult use only. It is not intended for use in children. 

Compro (Prochlorperazine) Drug Information: A person with their brain showing

Verywell / Zoe Hansen

How to Take Compro

Please consult with your healthcare provider on how much medication to use. Don’t use more than directed. Compro suppositories are for rectal use only (in the rectum) and should not be taken by mouth. 

Before using this medication, it is important to wash your hands with soap and water. Remove the foil wrapper before inserting the suppository into your rectum when ready for use. After administration, avoid contact with your eyes and wash your hands with soap and water immediately. Do not remove the suppository from its wrapper until you're ready to use it. Avoid having a bowel movement for an hour or longer so the drug will be absorbed.

If you realize that the suppository is too soft to handle before removing the wrapper, you may place it in the refrigerator for 20 to 30 minutes or hold it under cold water for a few minutes while the wrapper is still on. You may use a lubricating gel-like K-Y Jelly to make the suppository easier to insert, but do not use petroleum jelly (Vaseline). If you do not want to use a lubricating gel, you can gently wet the suppository with cool water to make it easier to administer.

To correctly insert the suppository into your rectum: 

  • Lie on your left side with your left leg straight or slightly bent, and your right knee bent upward. 
  • Gently push the pointed end of the suppository into the rectum about 1 inch. 
  • After inserting, remain lying down for 15 minutes to prevent the suppository from coming out before it melts. 


Because Compro is a rectal suppository, it can easily melt at high temperatures. It is important to store your suppositories at room temperature (between 68 and  77 degrees Fahrenheit) in a closed container, away from heat, moisture, and direct light. Do not store your medications in the bathroom.

Keep all medicine out of the reach of children. Never share your medicine with anyone.

Off-Label Uses 

Healthcare providers may prescribe Compro for off-label uses, meaning for conditions not specifically indicated by the Food and Drug Administration (FDA). 

Off-label uses of Compro include:

  • Moderate to severe nausea and vomiting symptoms associated with a sudden onset of a migraine.
  • Nausea and vomiting symptoms that occur as a result of opioid use.

What Are the Side Effects of Compro?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the FDA at or 1-800-FDA-1088.

Moderate Side Effects

Moderate side effects associated with Compro include, but may not be limited to, the following:

  • Blurred vision
  • Mild drowsiness
  • Restlessness or agitation
  • Insomnia

Severe Side Effects

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or think you’re having a medical emergency. Serious side effects can include the following:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, or trouble breathing
  • Neuroleptic malignant syndrome
  • Tardive dyskinesia, which can include uncontrolled jerky muscle movements (often in your face, tongue, or jaw)
  • Severe sleepiness
  • Unusual bleeding, bruising, or weakness
  • Yellow skin or eyes (jaundice)

Additional Counseling Tips

To help manage some of the side effects of Compro:

  • Stand up slowly when getting up suddenly from a lying or sitting position if you feel lightheaded.
  • Monitor your blood pressure regularly if you are at high risk of increased blood pressure. 
  • Avoid activities that may cause you to become very cold, hot, or dehydrated since Compro may change how your body regulates temperature.
  • Take precautions to prevent illness and injury, as Compro can make you bleed, bruise, or get infections more easily.

This medication may also cause false readings on some types of pregnancy tests. Be sure to tell your healthcare provider that you are using this medication. 

Report any signs or symptoms of tardive dyskinesia, such as: 

  • Jerky muscle movements
  • Tongue thrusting
  • Facial grimacing/tics
  • Random movements of extremities

Watch out for signs or symptoms of neuroleptic malignant syndrome:

  • Sweating
  • Fever
  • Stupor
  • Unstable blood pressure
  • Muscular rigidity
  • Autonomic dysfunction

Tell your healthcare provider if you experience any of these symptoms. These may be signs of a more serious condition.

Report Side Effects

Compro may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Compro Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For rectal dosage form (suppository):
    • For severe nausea and vomiting:
      • Adults—25 milligrams (mg) 2 times a day.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose, please unwrap and insert a suppository as soon as you remember. If it is almost time for your next dose, wait until then to take your regular dose. Do not take extra medicine to make up for a missed dose.

Overdose: What Happens If I Take Too Much Compro?

Do not take more medication than directed by your healthcare provider.  

Overdose symptoms include: 

  • Extreme sedation or coma
  • Difficulty breathing
  • Seizures
  • Increased heart rate
  • Dry eyes
  • Urinary retention
  • Dry mucous membranes
  • Low blood pressure

What Happens If I Overdose on Compro?

If you think you or someone else may have overdosed on Compro, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking too much Compro, call 911 immediately.


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It is very important that your doctor should check the progress of you and your child at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Check with your doctor before using this medicine with alcohol or other medicines that affect the central nervous system (CNS). The use of alcohol or other medicines that affect the CNS with risperidone may worsen the side effects of this medicine, such as dizziness, poor concentration, drowsiness, unusual dreams, and trouble with sleeping. Some examples of medicines that affect the CNS are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicines, medicine for depression, medicine for anxiety, prescription pain medicine or narcotics, medicine for attention deficit and hyperactivity disorder, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics.

This medicine may cause extrapyramidal symptoms. Check with your doctor right away if you have difficulty in speaking, drooling, loss of balance control, muscle trembling, jerking, or stiffness, restlessness, shuffling walk, stiffness of the limbs, twisting movements of the body, or uncontrolled movements, especially of the face, neck, and back.

This medicine may cause drowsiness, trouble with thinking, or trouble with controlling body movements, which may lead to falls, fractures or other injuries. Make sure you know how you react to this medicine before you drive, use machines, or do other jobs that require you to be alert, well-coordinated, or able to think or see well.

Dizziness, lightheadedness, or fainting may occur, especially when you get up suddenly from a lying or sitting position. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.

This medicine may make it more difficult for your body to cool itself down. Use care not to become overheated during exercise or hot weather since overheating may result in heat stroke. Also, use extra care not to become too cold while you are receiving risperidone injection. If you become too cold, you may feel drowsy, confused, or clumsy.

Make sure any doctor or dentist who treats you knows that you are using prochlorperazine suppository. This medicine may affect the results of certain medical tests.

This medicine may cause tardive dyskinesia (a movement disorder). Check with your doctor right away if you have any of the following symptoms while using this medicine: lip smacking or puckering, puffing of the cheeks, rapid or worm-like movements of the tongue, uncontrolled chewing movements, or uncontrolled movements of the arms and legs.

Check with your doctor right away if you have any of the following symptoms while using this medicine: convulsions (seizures), difficulty with breathing, a fast heartbeat, a high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. These could be symptoms of a serious condition called neuroleptic malignant syndrome (NMS).

Prochlorperazine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Compro? 

Compro should not be used in older adults (65 and older) with dementia- or delirium-related psychosis being treated with antipsychotic drugs because of an increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia).

Compro may make you feel dizzy or drowsy and cause trouble with thinking or controlling body movements, which may lead to falls, fractures, or other injuries. It should be avoided in older adults with a history of falls, fractures, or cognitive impairment. In addition, older individuals with Parkinson’s disease and men with lower urinary tract symptoms or benign prostatic hyperplasia (BPH) should also avoid using Compro, as it can worsen these conditions. 

Tell your healthcare provider if you have:

  • Liver disease
  • Heart disease
  • Parkinson’s disease
  • Blood or bone marrow problems
  • Bowel blockage
  • Brain tumor
  • Glaucoma
  • Low blood pressure
  • Pheochromocytoma
  • Reye syndrome
  • Seizures
  • A history of breast cancer

Compro may cause the following problems:

  • Extrapyramidal reaction (a muscle and nerve disorder)
  • Neuroleptic malignant syndrome (a nerve disorder that could be life-threatening)
  • Tardive dyskinesia (a muscle disorder that could become permanent)

 Also, let your healthcare provider know if you are pregnant or breastfeeding. This medication can potentially cause problems in the newborn baby if taken in the last few months of pregnancy.

What Other Medications Interact With Compro?

While taking Compro, avoid large doses of central nervous system (CNS) depressants such as barbiturates, alcohol, or narcotics. Using other phenothiazine antipsychotic drugs like chlorpromazine may interact with Compro, affecting your heart rate (prolonged QT interval). Some medicines can affect how well Compro works. Tell your healthcare provider if you are using any of the following:

  • Lithium
  • Blood pressure or heart medicine (e.g., guanethidine, propranolol)
  • Blood thinner (including warfarin)
  • A diuretic (water pill)
  • Medicine to treat seizures (including phenytoin)

Do not drink alcohol while you are using this medicine. Tell your healthcare provider if you use anything else that makes you sleepy. Some examples include allergy medicine, narcotic pain medicine, and alcohol. Ask your healthcare provider or pharmacist before using Compro with other medications, including over-the-counter (OTC) medicines, vitamins, and herbal products.

What Medications Are Similar?

There are currently no comparable medications to Compro of the same formulation or drug class that are authorized for the same use by the FDA.

Promethegan (promethazine) rectal suppository is in the same class as Compro, but it is only approved for the treatment and/or prevention of motion sickness. Compro should not be used with Promethegan. Ask your pharmacist or a healthcare provider if you have questions.

Frequently Asked Questions

  • What is Compro used for?

    Compro is a rectal suppository used to treat severe nausea and vomiting in adults. It is generally dosed twice daily with directions to unwrap and insert the suppository every 12 hours as needed.

  • How does Compro work?

    Once unwrapped and inserted, Compro suppositories melt within 15 minutes, allowing the drug to be absorbed into your body. It takes roughly 60 minutes for the medication to reduce nausea and vomiting by blocking dopamine (D1 and D2) receptors in the vomiting center and chemoreceptor trigger zone of the brain. Its duration of action can last from three to 12 hours. It is important to wash hands with soap and water before and after use.

  • What are the side effects of Compro?

    Some common effects of Compro include dizziness, blurred vision, sleepiness, and restlessness. More severe side effects include unusual bleeding, bruising, weakness, and uncontrollable jerking muscle movement. See the side effects section for a more comprehensive list.

How Can I Stay Healthy While Taking Compro?

Compro can help you manage your nausea and vomiting. There are steps you can take to stay healthy while taking this medication. 

Washing your hands with soap and water before and after use with Compro is your first step in maintaining good hygiene practices while using this medication. It can also be beneficial to understand your triggers for nausea and vomiting to learn other methods for preventing nausea and vomiting.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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