From Dr M.Xuereb MD

Co-Proxamol is a comparatively ineffective pain killer. This relic of the 1960s is a combination of a subtherapeutic dose of

paracetamol (only 325mg per tablet) and dextropropoxyphene, a weak opioid which is converted in the liver to a long acting compound.

There is scant evidence that Co-proxamol is superior to paracetamol alone in patients with moderate pain. The risk of dying from an overdose is 28 times greater than with paracetamol alone and 2.3 times greater than with tricyclic antidepressants, according to Professor Hawton based at Oxford University.

The UK’s concern with tricyclic antidepressant overdose fatalities has already prompted legislation for safer antidepressants to be used as first line agents (so-called SSRIs).

Co-Proxamol is hard to treat an overdose case because it causes liver toxicity, slows down respiration and triggers fatal abnormalities in the heart beat. It also acts fast and exerts its effects before the patient has time to be found or before he /she reaches hospital. Death can thus occur within the hour. In the UK, it cause 300 to 400 deaths per year.

Last month, the above facts instigated the Medicines and Healthcare products Regulatory Agency – the UK government’s watchdog on safety of medicines – to withdraw the drug. It advocated that the drug of choice for acute pain is paracetamol, followed by non steroidal anti inflammatory drugs (NSAIDs) and adding low and full dose opioids for longstanding pain.

Unfortunately, Co-Proxamol overdoses occur in Malta too.

Mark Xuereb

Oxford

UK