Meptid tablets and injection contain the active ingredient meptazinol, which is a type of medicine called an opioid analgesic (painkiller). It is related to morphine.

What is it used for?

  • Meptid tablets are used for the short-term treatment of moderate pain.
  • Meptid injection is used for the treatment of moderate to severe pain, including pain during childbirth, pain following surgery and pain due to kidney stones (renal colic).

How does it work?

  • Meptid tablets and injection contain the active ingredient meptazinol, which is a type of medicine called an opioid analgesic (painkiller). It is related to morphine.
  • Opioid painkillers work by mimicking the action of naturally occurring pain-reducing chemicals called endorphins. Endorphins are found in the brain and spinal cord and reduce pain by combining with opioid receptors.
  • Meptazinol mimicks the action of natural endorphins by combining with the opioid receptors in the brain and spinal cord. This blocks the transmission of pain signals sent by the nerves to the brain.
Therefore, even though the cause of the pain may remain, less pain is actually felt.

Use with caution in

  • Elderly people
  • Decreased liver function
  • Moderate to severely decreased kidney function
  • People with severe breathing problems
  • Asthma (avoid during an attack)
  • Underactive thyroid gland (hypothyroidism)
  • Low blood pressure (hypotension)
  • Convulsive disorders such as epilepsy
  • Enlarged prostate gland (prostatic hypertrophy)

Not to be used in

  • Alcohol intoxication (acute alcoholism)
  • Head injury
  • Raised pressure inside the skull (raised intracranial pressure)
  • Heart attack
  • People with a risk of a failure in function of part of the gut, causing an obstruction in the intestines (paralytic ileus)
  • People who have taken a monoamine-oxidase inhibitor (MAOI) in the last 14 days.
  • The injection should not be used in people with a tumour of the adrenal gland (phaeochromocytoma).
  • This medicine is not recommended for children.
  • This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine should not be used during pregnancy unless considered essential by your doctor, and only if the expected benefit to the mother is greater than any possible risk to the foetus. Seek medical advice from your doctor.
  • It is not known if this medicine passes into breast milk. It should not be used by breastfeeding mothers unless considered essential by your doctor, and only if the expected benefit to the mother is greater than any possible risk to the baby. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

  • Nausea and vomiting
  • Dizziness
  • Drowsiness
  • Constipation
  • Diarrhoea
  • Abdominal pain
  • Indigestion
  • Sweating
  • Headache
  • Balance problems involving the inner ear (vertigo)
  • Skin rashes
  • Low blood pressure (hypotension)
  • Slow, shallow breathing (respiratory depression)
  • Confusion
  • Hallucinations

The side effects listed above may not include all of the side effects reported by the drug's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines during treatment this one, to ensure that the combination is safe.

This medicine should not be taken at the same time as, or within 14 days of taking a monoamine oxidase inhibitor (MAOI), for example the antidepressants phenelzine, tranylcypromine or isocarboxacid.

There may be an increased risk of drowsiness and sedation if this medicine is taken with any of the following (which can also cause drowsiness):

  • alcohol
  • antipsychotics, eg haloperidol
  • barbiturates, eg phenobarbital, amobarbital
  • benzodiazepines, eg diazepam, temazepam
  • other opioids, eg morphine, codeine
  • sedating antihistamines, eg chlorphenamine, hydroxyzine
  • sleeping tablets, eg zopiclone
  • tricyclic antidepressants, eg amitriptyline.

The manufacturer recommends that this medicine is avoided in people taking ritonavir for HIV infection, as ritonavir may increase the blood level of meptazinol and thus increase the risk of side effects.

Cimetidine may also increase the blood level of meptazinol and thus increase the risk of side effects.

References:

https://www.drugs.com/uk/meptid-tablets-200mg-leaflet.html

http://www.medicines.ie/medicine/14317/SPC/Meptid+200+mg+Film-Coated+Tablets/

https://www.medicines.org.uk/emc/medicine/21233

https://patient.info/medicine/meptazinol-for-pain-relief-meptid

http://www.netdoctor.co.uk/medicines/aches-and-pains/a7080/meptid/

https://www.babycentre.co.uk/a542573/meptid-meptazinol