Meperidine Hcl

See also Warning section.

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 opioid agonist-antagonists such as butorphanol, nalbuphine, pentazocine), naltrexone, samidorphan.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, 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 used with other products that may also cause drowsiness or breathing problems. Tell your doctor or pharmacist if you are taking other products such as other opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

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.

Other medications can affect the removal of meperidine from your body, which may affect how meperidine works. Examples include azole antifungals (such as ketoconazole), macrolide antibiotics (such as erythromycin), mifepristone, rifamycins (such as rifabutin), ritonavir, drugs used to treat seizures (such as carbamazepine, phenytoin), among others.

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

Do not share this medication with others. Sharing 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.

Not applicable.

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 a substance use disorder (such as overuse of or addiction to 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), a certain adrenal gland tumor (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. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

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.

During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Discuss the risks and benefits with your doctor. (See also Warning section.)

This drug passes into breast milk and may have undesirable effects on a nursing infant. Tell the doctor right away if your baby develops unusual sleepiness, difficulty feeding, or trouble breathing. Consult your doctor before breastfeeding.

Meperidine has a risk for abuse and addiction, which can lead to overdose and death. Meperidine may also cause severe, possibly fatal, breathing problems. To lower your risk, your doctor should have you take the smallest dose of meperidine that works, and take it for the shortest possible time. See also How to Use section for more information about addiction.

Ask your doctor or pharmacist if you should have medication available to treat opioid overdose (such as naloxone, nalmefene). Teach your family or household members about the signs of an opioid overdose and how to treat it.

The risk for severe breathing problems is higher when you start this medication and after a dose increase, or if you take the wrong dose/strength. Taking this medication with alcohol or other drugs that can cause drowsiness or breathing problems may cause very serious side effects, including death. Also, other medications can affect the removal of meperidine from your body, which may affect how meperidine works. Be sure you know how to take meperidine and what other drugs you should avoid taking with it. See also Drug Interactions section. Get medical help right away if any of these very serious side effects occur: slow/shallow breathing, unusual lightheadedness, severe drowsiness/dizziness, difficulty waking up.

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

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, take the smallest effective dose for the shortest possible time. Babies born to mothers who use this drug for a long time may develop severe (possibly fatal) withdrawal symptoms. Tell the doctor right away if you notice any symptoms in your newborn baby such as crying that doesn't stop, slow/shallow breathing, irritability, shaking, vomiting, diarrhea, poor feeding, or difficulty gaining weight.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, give them naloxone or nalmefene if available, then call 911. If the person is awake and has no symptoms, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: slow/shallow breathing, severe drowsiness, coma.

Read the Medication Guide provided by your pharmacist before you start taking meperidine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

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. Make sure not to confuse the dose of meperidine liquid in milligrams (mg) with the dose in milliliters (mL). Ask your pharmacist or doctor to show you the right way to measure your 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, response to treatment, and other medications you may be taking. Children's dosage is also based on weight. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). 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.

Suddenly stopping this medication may cause withdrawal, especially if you have used it for a long time or in high doses. To prevent withdrawal, your doctor may lower your dose slowly. Tell your doctor or pharmacist right away if you have any withdrawal symptoms such as restlessness, mental/mood changes (including anxiety, trouble sleeping, thoughts of suicide), watering eyes, runny nose, nausea, diarrhea, sweating, muscle aches, or sudden changes in behavior.

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.

Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a mental/mood disorder or a substance use disorder (such as overuse of or addiction to drugs/alcohol). Take this medication exactly as prescribed to lower the risk of addiction. Ask your doctor or pharmacist for more details.

Tell your doctor if your pain does not get better or if it gets worse, or if you have any new pain.

See also Warning section.

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

To prevent constipation, eat dietary fiber, drink enough water, and exercise. You may also need to take a laxative. Ask your pharmacist which type of laxative is right for you.

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

Remember that this medication has been prescribed because your doctor 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: interrupted breathing during sleep (sleep apnea), mental/mood changes (such as agitation, confusion, hallucinations), trouble swallowing, stomach/abdominal pain, difficulty urinating, slow/irregular/fast heartbeat, shaking (tremors), vision changes, signs of your adrenal glands not working well (such as loss of appetite, unusual tiredness, weight loss).

Get medical help right away if you have any very serious side effects, including: fainting, seizure, severe 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 or at www.fda.gov/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.

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