Active Ingredients

Pethidine – Effect, Application & Risks


Pethidine is a fully synthetic opioid . It is used for severe to very severe pain , which can occur after accidents or operations, for example.

What is pethidine?

Pethidine is the oldest fully synthetic opioid. It was first synthesized in 1937. In Germany it is gradually being replaced by younger preparations, but worldwide it is still considered one of the most important strong analgesics .

The structure of pethidine is a simplified replica of the atropine molecule. It is made in a two-step synthesis. In medicines, pethidine is a white, crystalline powder that is easily soluble in water. It is considered a narcotic and as such is only available with a doctor’s prescription and is therefore subject to strict controls. Pethidine can be found on the market as a solution for injection or in the form of tablets, and suppositories are also available.

Pharmacological action

Since pethidine belongs to the group of opioid painkillers, its effect is unfolded at the so-called opioid receptors in the brain . The active substance imitates the body’s own messenger substances . By binding to the receptors, these inhibit the transmission of pain sensation and pain perception.

Pethidine ensures that even very severe pain is perceived by the patient as less extreme than it actually is. Accordingly, pethidine has a similar effect to morphine , but is five times weaker and therefore has a lower mood-elevating effect.

Pethidine exhibits analgesic, antitussive, spasmolytic, respiratory depressant and sedative effects. It helps lower blood pressure and increase heart rate . Administration is possible orally, rectally, intramuscularly and intravenously.

Medical Application & Use

Pethidine is used in the treatment of moderate to very severe acute and persistent pain as soon as non-opioid painkillers or weak opioids are ineffective. It is used, among other things, for pain caused by tumors , pain caused by a myocardial infarction or also in the context of postoperative analgesia . It is also effective for postoperative tremors . Furthermore, pethidine is used in the treatment of colic and also pancreatitis (acute or chronic inflammation of the pancreas).

Since pethidine forms the active metabolite norphetidine, it is not suitable for long-term therapy because norphetidine can lead to seizures . The duration of action of pethidine is about 2 to 4 hours. When administered intravenously, the maximum effect is already reached after about 3 to 10 minutes, when administered intramuscularly the effect reaches its peak after about 20 to 40 minutes.

Pethidine is contraindicated, among other things, in hypersensitivity reactions to the active ingredient, respiratory failure , acute bronchial asthma , certain cardiac arrhythmias , increased intracranial pressure , convulsions, diabetic acidosis , alcoholism and drug addiction , severe liver disease or Addison’s disease (primary adrenal cortical insufficiency ).

It is also not recommended for people with low blood pressure , impaired kidney function , thyroid dysfunction ( overactive or underactive ) or urethral diseases.

Pethidine should also not be taken during the first three months of pregnancy , but it can be used as a painkiller in its lowest possible dose during childbirth . Pethidine is not suitable for use in children and adolescents up to the age of 16.

Risks & side effects

The side effects that frequently occur when pethidine is administered include a drop in blood pressure , respiratory dysfunction , tachycardia or a slow heartbeat , increase in intracranial pressure, dizziness , drowsiness , changes in mood , impaired perception , delusions and agitation.

If pethidine is injected into the vein very quickly , it can also lead to bronchial spasms, nausea and vomiting , hiccups and constriction of the pupils . Long-term use of pethidine may result in constipation or difficulty voiding .

It can also lead to spasms in the bile ducts , impaired kidney function or allergic hypersensitivity reactions . If pethidine is injected into a vein, red wheals and pain may form along the blood vessel in question.

If pethidine is taken at the same time as antiepileptics or painkillers, undesirable interactions can also occur, such as a weakening or strengthening of the effect of pethidine or the other drug.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.