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Demerol Side Effects

Generic Name: meperidine

Note: This page contains information about the side effects of meperidine. Some of the dosage forms included on this document may not apply to the brand name Demerol.

For the Consumer

Applies to meperidine: oral solution, oral syrup, oral tablet

Other dosage forms:

In addition to its needed effects, some unwanted effects may be caused by meperidine (the active ingredient contained in Demerol). In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking meperidine:

Incidence not known:
  • Blurred vision
  • chest pain or discomfort
  • cold, clammy skin
  • confusion
  • convulsion
  • cough
  • decrease in the frequency of urination
  • decrease in urine volume
  • difficult or troubled breathing
  • difficulty in passing urine (dribbling)
  • difficulty with swallowing
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fainting
  • fast, slow, pounding, or irregular heartbeat
  • feeling of warmth
  • hives
  • irregular, fast, slow, or shallow breathing
  • itching
  • lightheadedness, dizziness, or fainting
  • muscle twitching or jerking
  • painful urination
  • pale or blue lips, fingernails, or skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • redness of the face, neck, arms, and occasionally, upper chest
  • rhythmic movement of the muscles
  • shakiness in the legs, arms, hands, or feet
  • shortness of breath
  • skin rash
  • sweating
  • tightness in the chest
  • trembling or shaking of the hands or feet
  • unusual tiredness or weakness
  • upper abdominal or stomach pain
  • wheezing

If any of the following symptoms of overdose occur while taking meperidine, get emergency help immediately:

Symptoms of overdose:
  • Bluish color of the fingernails, lips, skin, palms, or nail beds
  • change in consciousness
  • decreased awareness or responsiveness
  • loss of consciousness
  • severe sleepiness
  • sleepiness or unusual drowsiness

Minor Side Effects

Some of the side effects that can occur with meperidine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Drowsiness
  • nausea
  • relaxed and calm
  • vomiting
Incidence not known:
  • Anxiety
  • blurred or loss of vision
  • confusion about identity, place, and time
  • difficulty having a bowel movement (stool)
  • disturbed color perception
  • double vision
  • dry mouth
  • false or unusual sense of well-being
  • halos around lights
  • headache
  • hives or welts
  • hyperventilation
  • irritability
  • nervousness
  • night blindness
  • overbright appearance of lights
  • redness of the skin
  • restlessness
  • seeing, hearing, or feeling things that are not there
  • trouble with sleeping
  • tunnel vision
  • weakness

For Healthcare Professionals

Applies to meperidine: compounding powder, injectable solution, intravenous solution, oral syrup, oral tablet


The most frequently reported adverse reactions have included lightheadedness, dizziness, sedation, nausea, vomiting, and sweating.[Ref]


Frequency not reported: Respiratory depression, respiratory arrest[Ref]

Nervous system

Frequency not reported: Serotonin syndrome, hyperexcitability, convulsions, weakness, headache, tremor, involuntary muscle movements (e.g. muscle twitches, myoclonus), delirium, dizziness, drowsiness, fainting, neurotoxicity, lightheadedness[Ref]

Therapeutic doses of this drug have precipitated unpredictable, severe, and occasionally fatal reactions in patients who have received MAOIs within 14 days of receiving this drug. The mechanism of this reaction is unclear, but may be related to preexisting hyperphenylalaninemia. Reactions have included coma, severe respiratory depression, cyanosis, and hypotension. IV hydrocortisone or prednisolone have been used to treat severe reactions, with IV chlorpromazine used in cases exhibiting hypertension and hyperpyrexia. The usefulness and safety of narcotic antagonists is unknown.

Neurotoxicity associated with increased concentrations of active metabolite have occurred. Reactions have included a range of excitatory effects including tremor, hallucinations, seizures, coma, and mood changes.[Ref]


Frequency not reported: Mood changes (e.g. euphoria, dysphoria), agitation, transient hallucinations and disorientation, confusion, dependence, anxiety, nervousness[Ref]


Frequency not reported: Severe hypotension, orthostatic hypotension, syncope, shock, cardiac arrest, circulatory depression, flushing, tachycardia, bradycardia, palpitations, hypotension, hypertension[Ref]


Frequency not reported: Wheel and flare over the vein with IV injection, hypersensitivity reactions, anaphylaxis, histamine release leading to hypotension and/or tachycardia, sweating, flushing, and pruritus[Ref]


Frequency not reported: Sensory-motor paralysis, phlebitis, injection site pain, local tissue irritation and induration following subcutaneous injection[Ref]

Inadvertent injection about a nerve trunk may result in sensory-motor paralysis which is usually transitory. Phlebitis has been reported following IV injection.[Ref]


Frequency not reported: Vertigo, hypothermia[Ref]


Frequency not reported: Urinary retention, micturition difficulties, decreased libido, renal colic, anuria[Ref]


Frequency not reported: Dry mouth, constipation, biliary tract spasm, nausea, vomiting, decreased gastric emptying[Ref]


Frequency not reported: Pruritus, urticaria, other skin rashes, sweating[Ref]


Frequency not reported: Muscle twitching, muscle rigidity[Ref]


Frequency not reported: Adrenal insufficiency, androgen deficiency[Ref]


Frequency not reported: Biliary spasm, choledochoduodenal sphincter spasm[Ref]


Frequency not reported: Antidiuretic effect[Ref]


Frequency not reported: Visual disturbances, dry eye, pupillary constriction, miosis, decreased corneal reflex, mydriasis[Ref]


Frequency not reported: Anorexia[Ref]


1. Cerner Multum, Inc. "Australian Product Information." O 0

2. "Product Information. Demerol HCl (meperidine)." Validus Pharmaceuticals Inc, Parsippany, NJ.

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Not all side effects for Demerol may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.