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Meperidine is used to help relieve moderate to severe pain. It belongs to a class of drugs known as narcotic (opioid) analgesics and is similar to morphine. It works in the brain to change how your body feels and responds to pain.

Meperidine should not be used to treat long-term or ongoing pain. It should only be used to treat sudden episodes of moderate to severe pain. See also Precautions section.

How to use Demerol

Take this medication by mouth as directed by your doctor, usually every 3 to 4 hours as needed. You may take this drug with or without food. If you have nausea, it may help to take this drug with food. Ask your doctor or pharmacist about other ways to decrease nausea (such as lying down for 1 to 2 hours with as little head movement as possible).

If you are using the liquid form of this medication, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. Mix your dose with one-half glass of water (4 ounces/120 milliliters) and drink right away. Mixing your dose in water before you take it will prevent your mouth from becoming numb.

The dosage is based on your medical condition and response to treatment. Do not increase your dose or use this drug more often or for longer than prescribed because your risk of side effects may increase. Properly stop the medication when so directed.

Pain medications work best if they are used as the first signs of pain occur. If you wait until the pain has worsened, the medication may not work as well.

This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as restlessness, watering eyes, runny nose, nausea, sweating, muscle aches) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Ask your doctor or pharmacist for more details, and report any withdrawal reactions right away.

When this medication is used for a long time, it may not work as well. Talk with your doctor if this medication stops working well.

Along with its benefits, this medication may rarely cause abnormal drug-seeking behavior (addiction). This risk may be increased if you have abused alcohol or drugs in the past. Take this medication exactly as prescribed to lessen the risk of addiction.

Tell your doctor if your pain persists or worsens.

Keep this medicine in a safe place to prevent theft, misuse, or abuse. If a child accidentally swallows this drug, get medical help right away.

Side Effects

Nausea, vomiting, constipation, sweating, lightheadedness, dizziness, or drowsiness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

To prevent constipation, eat a diet adequate in fiber, drink plenty of water, and exercise. Consult your pharmacist for help in selecting a laxative (such as a stimulant type with stool softener).

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as agitation, confusion, hallucinations), stomach/abdominal pain, difficulty urinating, slow/irregular/fast heartbeat, shaking (tremors), vision changes.

Meperidine has a high risk for abuse and severe, possibly fatal, breathing problems. The risk for harm is higher if you take the wrong dose/strength, or if you take it along with other drugs that might also affect breathing. Be sure you know how to take meperidine and what other drugs you should avoid taking with it. See also Drug Interactions section. The risk for breathing problems might also be higher when you start this medication and after a dose increase. Get medical help right away if you notice: unusual slow/shallow breathing.

Get medical help right away if you have any very serious side effects, including: fainting, seizure, unusual drowsiness/difficulty waking up.

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.


Before taking meperidine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before taking this medication, tell your doctor or pharmacist your medical history, especially of: brain disorders (such as head injury, tumor, seizures), breathing problems (such as asthma, sleep apnea, chronic obstructive pulmonary disease-COPD), gallbladder disease, kidney disease, liver disease, mental/mood disorders (such as confusion, depression, thoughts of suicide), personal or family history of regular use/abuse of drugs/alcohol, stomach/intestinal problems (such as blockage, constipation, diarrhea due to infection, paralytic ileus), disease of the pancreas (pancreatitis), difficulty urinating (such as due to enlarged prostate), pheochromocytoma, heart problems (such as fast/irregular heartbeat), sickle cell anemia.

Meperidine is usually used only for a short time. Repeated or high doses may cause drug levels to build up in the body and cause serious side effects such as seizures and shaking. Caution is advised if this medication is used for conditions that require long-term or high-dosage treatment (such as sickle cell anemia, burns, cancer). Consult your doctor or pharmacist for details.

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially confusion, dizziness, drowsiness, and slow/shallow breathing.

Children may be more sensitive to the side effects of this drug, especially severe drowsiness and slow/shallow breathing.

Before using this medication, women of childbearing age should talk with their doctor(s) about the risks and benefits. Tell your doctor if you are pregnant or if you plan to become pregnant. During pregnancy, this medication should be used only when clearly needed. It may slightly increase the risk of birth defects if used during the first two months of pregnancy. Also, using it for a long time or in high doses near the expected delivery date may harm the unborn baby. To lessen the risk, use the smallest effective dose for the shortest possible time. Tell the doctor right away if you notice any symptoms in your newborn baby such as crying that isn't normal and doesn't stop, slow/shallow breathing, irritability, vomiting, or diarrhea.

This drug passes into breast milk and is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.


Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include: certain pain medications (mixed narcotic agonist-antagonists such as pentazocine, nalbuphine, butorphanol), narcotic antagonists (such as naltrexone, naloxone), ritonavir.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.

The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also affect breathing or cause drowsiness. Tell your doctor or pharmacist if you are taking other products such as alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), and other narcotic pain relievers (such as codeine, hydrocodone).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

This medication may interfere with certain laboratory tests (including amylase/lipase tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.


If overdose is suspected, contact a poison control center or emergency room right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: slow/shallow breathing, severe drowsiness, loss of consciousness.


Do not share this medication with others. It is against the law.

This medication has been prescribed for your current condition only. Do not use it later for another condition unless your doctor directs you to do so. A different medication may be necessary in that case.

Missed Dose

Not applicable.


Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. In the US, the FDA recommends flushing this medication down the toilet or pouring into a drain. Consult your pharmacist or local waste disposal company.

Information last revised June 2015. Copyright(c) 2015 First Databank, Inc.


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D 35, logo
This medicine is a white, round, scored tablet imprinted with "D 35" and "logo".


logo, D 37
This medicine is a white, round tablet imprinted with "logo" and "D 37".

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Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

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