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Generic Name: meperidine and promethazine (me-PER-i-deen and proe-METH-a-zeen)
Brand Name: Generic only. No brands available.

Meprozine should not be used in children younger than 2 years old. Potentially fatal side effects (eg, difficult or slowed breathing, drowsiness leading to coma) may occur in this age group when taking a medicine that has promethazine in it.

Caution should be used when using Meprozine in children 2 years old and older. The lowest possible dose should be used in this age group, and it should not be used with other medicines that cause slowed breathing.

Meprozine is used for:

Treating moderate to moderately severe pain.

Meprozine is a narcotic analgesic and phenothiazine antihistamine combination. The narcotic analgesic works in the brain and nervous system to decrease pain. The phenothiazine antihistamine works by blocking the sites where histamine acts.

Do NOT use Meprozine if:

  • you are allergic to any ingredient in Meprozine
  • you have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) within the last 14 days
  • you have severe central nervous system depression or are in a coma

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

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 or have recently had any head injury, brain tumor or other growths, or increased pressure in the brain
  • if you have lung or breathing problems (eg, asthma, chronic obstructive pulmonary disease [COPD]), certain heart problems (eg, cor pulmonale, irregular heartbeat), low levels of oxygen in the blood (hypoxia), high levels of carbon dioxide in the blood (hypercapnia), stomach pain, kidney problems, liver problems, severe weakness, poor health, thyroid problems, adrenal gland problems (eg, Addison disease, pheochromocytoma), sickle cell anemia, drowsiness, curvature of the spine (scoliosis), low blood pressure, low blood volume, prostate problems, or urinary blockage or trouble urinating
  • if you have a history of seizures
  • if you drink alcohol or are going through withdrawal from alcohol or other substances

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

  • MAOIs (eg, phenelzine) because the risk of serious side effects, including coma, difficulty breathing, low blood pressure, seizures, and irregular heartbeat, may be increased
  • Barbiturates (eg, phenobarbital), other narcotic pain medicines (eg, oxycodone), phenothiazines (eg, chlorpromazine), sleep medicines (eg, zolpidem), or tricyclic antidepressants (eg, amitriptyline) because they may increase the risk of Meprozine's side effects

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 stomach upset occurs, take with food to reduce stomach irritation.
  • If you miss a dose of Meprozine and you are using it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. 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 or dizziness. 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.
  • Meprozine may cause dizziness, light-headedness, or fainting; alcohol, hot weather, exercise, or fever can 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.
  • Check with your doctor before you 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 constipation. Talk with your doctor or pharmacist about using a stool softener or laxative to prevent constipation. It is also important to maintain a diet adequate in fiber, drink plenty or water, and exercise to prevent constipation. If you become constipated while taking Meprozine, talk with your doctor or pharmacist.
  • 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.
  • Meprozine may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Meprozine. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
  • Tell your doctor or dentist that you take Meprozine before you receive any medical or dental care, emergency care, or surgery.
  • Use Meprozine with extreme caution in the ELDERLY; they may be more sensitive to its effects.
  • Meprozine should not be used in CHILDREN younger than 2 years old. Serious, and sometimes fatal, side effects (difficult or slowed breathing, drowsiness leading to coma) have occurred when Meprozine has been used in children in this age group.
  • Meprozine should be used with extreme caution in CHILDREN 2 years old or older. The lowest effective dose should be used in children 2 years old or older.
  • 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 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.

When used for long periods of time or at high doses, some people develop a need to continue taking Meprozine. This is known as DEPENDENCE or addiction.

If you suddenly stop taking Meprozine, you may experience WITHDRAWAL symptoms, including 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; and 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; light-headedness; 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; confusion; fainting; fast, slow, or irregular heartbeat; fever, chills, or sore throat; hallucinations; mental or mood changes (eg, agitation, delirium, exaggerated sense of well-being, excitability, hysteria, nervousness); muscle problems with your tongue, face, mouth, or jaw (eg, tongue sticking out, puffing cheeks, mouth puckering, chewing); seizures; severe or persistent constipation; severe of persistent dizziness, drowsiness, or light-headedness; slow or shallow breathing or trouble breathing; tremor; uncontrolled muscle movements; unusual bruising or bleeding; vision changes; yellowing of 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.

Proper storage of Meprozine:

Store Meprozine at room temperature, between 68 to 77 degrees F (20 to 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 tightly closed. 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 should not be used to decide whether or not to take Meprozine 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 Meprozine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Meprozine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your health care provider for complete information about the risks and benefits of using Meprozine.

Issue Date: June 3, 2015