Milk of amnesia: a powerful anaesthetic abused all too often

Propofol has a potential for abuse (EPA)

Propofol is the most widely used anaesthetic drug in the US and the UK. Known as the "milk of amnesia" – it comes as a white liquid – it is given by infusion direct into a vein and rapidly induces unconsciousness followed by quick recovery, so patients can be up and about soon after surgery without feeling groggy or dazed.

At least 99 per cent is used in hospital operating theatres. The rest is used in accident and emergency departments and specialist clinics – for example to put a patient with a dislocated shoulder under for a few seconds while the joint is tweaked back into place.

It is not available on prescription and cannot be bought over the counter. GPs do not use it. But it is not a controlled drug, kept under lock and key, because it does not contain opiates (morphine).

A British consultant anaesthetist said yesterday: "Most of my colleagues were stunned by the idea that people could have cupboards of the stuff at home. I can't imagine it ever being used outside a hospital. It is a powerful sedative – it is not the sort of drug you hand out in a nursing home. I can't get my head around it."

Although propofol does not induce a feeling of euphoria like heroin, it does have a potential for abuse. Instead of the "high" associated with opiate drugs, it brings oblivion and a feeling of being slowed down and spaced out. Some people experience a sense of disinhibition followed by a feeling of calm and an upbeat mood. Once the drug wears off some say they feel rested, energetic and happy.

Propofol was introduced to the US in the 1980s and its popularity grew rapidly. Its big advantage over its predecessor drug in the UK, thiopentone (sodium thiopental in the US), was that it did not build up in the body, leaving patients slow to recover.

Anecdotal reports of abuse quickly emerged. A 2007 survey of academic anaesthetic departments in the US found that 18 per cent reported propofol abuse by doctors or nurses – a sixfold increase in a decade.

Known as Diprivan in the US, propofol is off-patent and generic versions are available at low prices. In the UK, a 20ml ampoule is priced at £3.46 and a 100ml bottle at £19.42 in the British National Formulary, but the cost to NHS hospitals would be much lower.

The drug is potent and can kill without constant observation and the availability of help to support breathing in the event of an overdose. There have been a number of propofol-linked deaths in the US of which Michael Jackson's is only one.