Generic Name: meperidine/promethazine (me-PER-i-deen/proe-METH-a-zeen)
Brand Name: Meprozine

Meprozine is used for:

Treating moderate pain and causing drowsiness in patients who have just had surgery or delivered a baby, or who have pain associated with cancer. It may also be used for other conditions as determined by your doctor.

Meprozine is a combination narcotic analgesic and phenothiazine. The narcotic works by dulling the pain perception center in the brain. The phenothiazine causes drowsiness.

Do NOT use Meprozine if:

  • you are allergic to any ingredient in Meprozine
  • you have a certain type of intestinal inflammation (pseudomembranous colitis) or diarrhea due to poisoning, severe drowsiness, or you are in a coma
  • you have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) within the last 14 days
  • you are taking astemizole, cisapride, ritonavir, sibutramine, sodium oxybate (GHB), or terfenadine

Contact your doctor or health care provider right away if any of these apply to you.

Slideshow: 2014 Update: First Time Brand-to-Generic Switches

Before using Meprozine:

Some medical conditions may interact with Meprozine. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have a history of breathing problems (eg, asthma, chronic obstructive pulmonary disease [COPD], cor pulmonale); low levels of oxygen or high levels of carbon dioxide in the blood; sickle cell anemia; low blood pressure; prostate problems; urinary blockage; lung, liver, or kidney problems; heart problems (eg, irregular heartbeat); seizures; or stomach or intestine problems (eg, inflammatory bowel disease)
  • if you have a history of head injury, brain tumor or other growths, increased pressure in the brain, adrenal tumor or other problems (eg, Addison disease, pheochromocytoma), curved spine, or an underactive thyroid
  • if you have a history of nervous system problems, bone marrow problems, blood problems (eg, porphyria), glaucoma or risk factors for glaucoma, increased eye pressure, Parkinson disease, or Reye syndrome
  • if you regularly consume alcohol or have a history of alcohol or substance abuse/dependence, delirium tremens, mental or mood changes caused by a medicine or other substance, or suicidal thoughts or attempts
  • if you are dehydrated, have been severely weakened, or have had recent surgery

Some MEDICINES MAY INTERACT with Meprozine. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Agonist/antagonist analgesics (eg, butorphanol, pentazocine) or naltrexone because they may decrease Meprozine's effectiveness
  • MAOIs (eg, phenelzine) because the risk of serious side effects, including coma, difficulty breathing, low blood pressure, seizures, and irregular heartbeat, may be increased
  • Astemizole, cisapride, haloperidol, or terfenadine because the risk of side effects, such as low blood pressure, seizure, or irregular heartbeat, may be increased
  • Acyclovir, cimetidine, HIV protease inhibitors (eg, ritonavir), phenothiazines (eg, chlorpromazine), phenytoin, or tricyclic antidepressants (eg, amitriptyline) because they may increase the risk of Meprozine's side effects
  • Sibutramine because the risk of side effects, including increased body temperature, mental or mood changes, muscle twitching, or severe drowsiness, may be increased
  • Barbiturate anesthetics (eg, thiopental), barbiturates (eg, phenobarbital), narcotic analgesics (eg, morphine), neuromuscular blockers (eg, pancuronium), or sodium oxybate (GHB) because the risk of their side effects may be increased by Meprozine
  • Epinephrine, levodopa, or pergolide because their effectiveness may be decreased by Meprozine

This may not be a complete list of all interactions that may occur. Ask your health care provider if Meprozine may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Meprozine:

Use Meprozine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Take Meprozine by mouth with or without food.
  • If Meprozine is no longer needed, dispose of it as soon as possible. Ask your doctor or pharmacist how to dispose of Meprozine properly.
  • If you miss a dose of Meprozine and you are taking it regularly, take it as soon as possible. If several hours have passed or if it is nearing time for the next dose, do not double the dose to catch up, unless advised by your health care provider. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Meprozine.

Important safety information:

  • Meprozine may cause drowsiness, dizziness, or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Meprozine with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Meprozine; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
  • Meprozine may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
  • Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.
  • Neuroleptic malignant syndrome (NMS) is a possibly fatal syndrome that can be caused by Meprozine. Symptoms may include fever; stiff muscles; confusion; abnormal thinking; fast or irregular heartbeat; and sweating. Contact your doctor at once if you have any of these symptoms.
  • Do not suddenly stop taking Meprozine without first checking with your doctor.
  • Tell your doctor or dentist that you take Meprozine before you receive any medical or dental care, emergency care, or surgery.
  • Use Meprozine with caution in the ELDERLY; they may be more sensitive to its effects.
  • Meprozine should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.
  • PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Meprozine while you are pregnant. Meprozine should not be used during labor or prior to the labor period because it may cause harmful side effects to the baby. Meprozine is found in breast milk. Do not breast-feed while using Meprozine.

When used for long periods of time or at high doses, Meprozine may not work as well and may require higher doses to obtain the same effect as when originally taken. This is known as TOLERANCE. Talk with your doctor if Meprozine stops working well. Do not take more than prescribed.

Some people who use Meprozine for a long time may develop a need to continue taking it. People who take high doses are also at risk. This is known as DEPENDENCE or addiction.

If you stop taking Meprozine suddenly, you may have WITHDRAWAL symptoms. These may include anxiety; appetite loss; backache; chills; diarrhea; enlarged pupils; fast heartbeat or breathing rate; increased tears; irritability; muscle or joint pain; nausea; restlessness; runny nose; severe or persistent dizziness; sleeplessness; stomach cramps; sweating; vomiting; weakness; yawning.

Possible side effects of Meprozine:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Constipation; dizziness; drowsiness; dry mouth; lightheadedness; loss of appetite; nausea; sweating; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; difficulty urinating; fainting; fast, slow, or irregular heartbeat; fever, chills, or persistent sore throat; mental or mood changes; numbness of an arm or a leg; rigid muscles; seizure; slowed or difficult breathing; severe or persistent dizziness or drowsiness; sudden severe headache, nausea, vomiting, or stomach pain; tremor; uncontrolled muscle movements; vision changes; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include chest pain; cold and clammy skin; lightheadedness; limp muscles; loss of consciousness; low body temperature; seizures; severe dizziness; severe drowsiness; slowed heartbeat; slowed or difficult breathing; small pupils.

Proper storage of Meprozine:

Store Meprozine at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Meprozine out of the reach of children and away from pets.

General information:

  • If you have any questions about Meprozine, please talk with your doctor, pharmacist, or other health care provider.
  • Meprozine is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Meprozine. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: July 2, 2014
Database Edition
Copyright © 2014 Wolters Kluwer Health, Inc.

Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.

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