Medical Editor: John P. Cunha, DO, FACOEP
What Is Demerol?
Demerol (meperidine) is an oral and injectable opiod used for treatment of moderate to severe pain.
What Are Side Effects of Demerol?
Common side effects of Demerol include:
- lightheadedness,
- dizziness,
- sedation,
- nausea,
- vomiting,
- sweating,
- constipation,
- loss of appetite,
- headache,
- weakness,
- dry mouth,
- itching,
- urinating less than usual,
- flushing,
- drowsiness, or
- loss of interest in sex.
Dosage for Demerol
The usual dose of Demerol for adults is 50 to 150 mg every 3 to 4 hours.
What Drugs, Substances, or Supplements Interact with Demerol?
Demerol may interact with other narcotic pain medications, sedatives, tranquilizers, muscle relaxers, other medicines that can make you sleepy or slow your breathing, phenytoin, pentazocine, nalbuphine, butorphanol, or buprenorphine. Tell your doctor all medications and supplements you use.
Demerol During Pregnancy and Breastfeeding
Demerol has not been adequately evaluated in pregnant women. Demerol is habit forming and may cause withdrawal symptoms. Tell your doctor if you are pregnant or plan to become pregnant while using Demerol. Demerol passes into breast milk and may harm a nursing baby. Breastfeeding while using Demerol is not recommended.
Additional Information
Our Demerol Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

QUESTION
Medically speaking, the term "myalgia" refers to what type of pain? See AnswerGet emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.
Stop using meperidine and call your doctor at once if you have:
- slow heartbeats, weak or shallow breathing, breathing that stops during sleep;
- severe drowsiness, feeling like you might pass out;
- confusion, mood changes;
- severe constipation;
- tremors, muscle movements you cannot control, or a seizure (convulsions); or
- low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.
Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.
Serious side effects may be more likely in older adults and those who are malnourished or debilitated.
Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.
Common side effects may include:
- dizziness, drowsiness;
- headache;
- nausea, vomiting; or
- sweating.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Read the entire detailed patient monograph for Demerol (Meperidine)

SLIDESHOW
Back Pain: 16 Back Pain Truths and Myths See SlideshowSIDE EFFECTS
The following serious adverse reactions are described, or described in greater detail, in other sections:
- Addiction, Abuse, and Misuse [see WARNINGS AND PRECAUTIONS]
- Life-Threatening Respiratory Depression [see WARNINGS AND PRECAUTIONS]
- Neonatal Opioid Withdrawal Syndrome [see WARNINGS AND PRECAUTIONS]
- Interactions with Benzodiazepines or Other CNS Depressants [see WARNINGS AND PRECAUTIONS]
- Serotonin Syndrome [see WARNINGS AND PRECAUTIONS]
- Adrenal Insufficiency [see WARNINGS AND PRECAUTIONS]
- Severe Hypotension [see WARNINGS AND PRECAUTIONS]
- Gastrointestinal Adverse Reactions [see WARNINGS AND PRECAUTIONS]
- Seizures [see WARNINGS AND PRECAUTIONS]
- Withdrawal [see WARNINGS AND PRECAUTIONS]
The following adverse reactions associated with the use of meperidine were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
The major hazards of meperidine, as with other opioid analgesics, are respiratory depression and, to a lesser degree, circulatory depression, respiratory arrest, shock, and cardiac arrest.
The most frequently observed adverse reactions included lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seem to be more prominent in ambulatory patients and in those who are not experiencing severe pain. In such individuals, lower doses are advisable. Some adverse reactions in ambulatory patients may be alleviated if the patient lies down.
Other adverse reactions include:
Nervous System
Mood changes (e.g., euphoria, dysphoria), weakness, headache, agitation, tremor, involuntary muscle movements (e.g., muscle twitches, myoclonus), severe convulsions, transient hallucinations and disorientation, confusion, delirium, visual disturbances.
Gastrointestinal
Dry mouth, constipation, biliary tract spasm.
Cardiovascular
lushing of the face, tachycardia, bradycardia, palpitation, hypotension [see WARNINGS AND PRECAUTIONS], syncope.
Genitourinary
Urinary retention.
Allergic
Pruritus, urticaria, other skin rashes, wheal and flare over the vein with intravenous injection. Hypersensitivity reactions, anaphylaxis.
Histamine release leading to hypotension and/or tachycardia, flushing, sweating, and pruritus.
Serotonin Syndrome
Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs.
Adrenal Insufficiency
Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.
Androgen Deficiency
Cases of androgen deficiency have occurred with chronic use of opioids [see CLINICAL PHARMACOLOGY].
To report SUSPECTED ADVERSE REACTIONS, contact Validus Pharmaceuticals LLC at 1866-982-5438 (1-866-9VALIDUS) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Read the entire FDA prescribing information for Demerol (Meperidine)
Read the Demerol User Reviews »
© Demerol Patient Information is supplied by Cerner Multum, Inc. and Demerol Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.
