- Hypersensitivity to Pethidine.
- Respiratory depression, or where respiratory reserve is depleted (acute bronchial asthma, chronic airway disease, severe emphysema, severe chronic bronchitis, kyphoscoliosis).
- Head injury, raised intracranial pressure (apart form introducing monitoring and diagnostic problems, hypercapnia associated with respiratory depression can itself result in elevated intracranial pressure), brain tumour.
- Cardiac arrythmias, especially supraventricular tachycardias, cor pulmonale. Pethidine has a vagolytic action and may produce a significant increase in the ventricular response rate.
- Concurrent use of monoamine oxidase inhibitors (MAOI’s), including selegeline, or use of MAOI’s within two weeks prior.
- The combination of monoamine oxidase inhibitors and pethidine has caused hypotension, hypertension, excitation, rigidity, hyperpyrexia and/or convulsions and in some cases fatalities have been reported. This combination should be avoided.
- Pre-eclampsia, eclampsia.
- Convulsive states such as status epilepticus, tetanus and strychnine poisoning, due to the stimulatory effects of pethidine on the spinal cord.
- Diabetic acidosis where there is a danger of coma.
- Acute alcoholism or delirium tremens.
- Severe liver disease, incipient hepatic encephalopathy.
- Patients with a low platelet count, coagulation disorders or receiving anticoagulant treatment.