Demerol (Meperidine) Side Effects, Important Information, Before Taking & More

Demerol is a pain relieving drug that is used by patients to get rid of bodily pains and discomfort. It is used to treat moderate to severe pains among adults. The medicine belongs to the class of drugs known as an opiate narcotic analgesic. It is found to be extremely helpful for people who may require medications to ease the pain caused by diseases such as osteoarthritis, joint pains, etc. 1

The medicine is usually prescribed to patients before or after medical procedures such as surgery, dental problems, injuries, childbirth or any other painful procedure. However, Demerol can only be of help if used to treat a sudden episode of mild or severe pain. It may not be of much help to treat long-term or ongoing pain.



Common side effects of Demerol

Although severe side effects of this medicine are rare, there have been instances of such effects on a few users. The major side effects of Demerol are mentioned below and will require immediate medical attention.

Major side effects

  • Rapid and pounding heartbeats
  • Hallucinations
  • Allergic reactions resulting in trouble breathing, hives, skin rash, etc.
  • Irregular breathing
  • Increased sweating
  • Redness or flushing of the face
  • Gradual disassociation from the family
  • Shortness of breath and wheezing
  • Symptoms of urinary retention such as little to no need to urinate or frequent urge to urinate, difficulty or burning while urinating, etc.



There are minor side effects of this drug too, but these are temporary and tend to go away once treatment is completed. It is possible you might not even experience any side effects at all.

Minor side effects

  • Weakness and lethargy
  • Drowsiness and dizziness
  • Mood swings
  • A headache
  • Constipation
  • Blurred or double vision
  • Dry mouth
  • Vomiting

These side effects are mild and are fairly common among users. They are not dangerous and do not require you to consult a doctor. However, if you notice these signs aggravating, see a doctor at once.


How does Demerol work?

Demerol works by altering the way the affected individual’s brain responds to bodily pain by increasing the levels of neurotransmitters. Neurotransmitters are natural substances that occur within the body and mediate the transfer of signals to and from the central nervous system and to different parts of the body. Demerol increases the levels of serotonin and norepinephrine in the brain which are known as feel-good neurotransmitters. Once the levels of these natural chemicals are increased, the user experiences less pain due to increased pain tolerance.


How to use Demerol?

The medicine needs to be injected in the skin of the abdomen, upper arm or thigh through an IV. Make sure not to inject in the same place two times in a row. Don’t attempt to inject into the skin by yourself until you fully understand the directions of your doctor. If you do not know how to do it, seek help from your healthcare provider. Ensure that your hands are washed, and the site of injection is also cleaned and dried. Make use of a disposable syringe and dispose it after each use, do not use the same needle again and again. The dosage of this drug may vary according to the patient’s medical condition. Do not alter dosages or overdose without a doctor’s recommendation as it can lead to serious side effects. Take the medicine as the first sign of pain appears, do not wait until it worsens as the medicine may not be as effective then.



  • Do not use this drug if you are allergic to it or its ingredients.
  • Avoid using this medicine if you have acute alcoholism, asthma, respiratory problems, abnormal heart rhythms, blockage of the gastrointestinal tract, epilepsy, depression, or have taken an MAO inhibitor in the last 2 weeks.
  • An overdose of this drug may result in serious side effects such as seizures and tremors.
  • May make you dizzy; do not engage in activities that require complete attention such as driving and operating machinery until fully alert.
  • Get up from a lying or a sitting position slowly to avoid falling over due to being dizzy.
  • Avoid alcohol consumption when taking this medicine as it may increase the risks of side effects
  • Children may be more sensitive to this drug, making them more drowsy and have shallow breathing.
  • Pregnant women should not use this medication as it may harm the unborn child.
  • Breastfeeding women should not use this medicine as it passes through breast milk and may have negative effects on the nursing child.