When Michael Jackson died, a relative, Richard, called me from abroad and asked, "What level of pain could Michael have been experiencing for him to be taking so many painkillers?" I realised at that point that some people may incorrectly believe that if Michael was taking strong painkillers, he must have been having severe physical pain.

It has also been alleged that Michael was using propofol (Diprivan), a general anaesthetic used to put a person to sleep during surgery, but in small doses may act as a sedative (a calming, soothing drug to put one to sleep). Michael reportedly had severe insomnia (inability to sleep). The truth is that until we receive the toxicology report from Michael's autopsy, we really won't know for sure whether he was taking anything at all.

Prescription painkillers

Strictly speaking, numerous prescription painkillers exist such as NSAIDs and anti-migraine drugs. However, in everyday speech, when we mention prescription painkillers, we usually mean opioid analgesics.

The big guns

Opioid analgesics are 'the big guns' in the painkilling armamentarium. There is hardly anything better than pain relief, especially when the pain is severe. So analgesics, including opioid analgesics, have an important role in health care. However, if you've ever had to fill a prescription for one of these drugs, you know how strict the process can be. The doctor is required to monitor the client for pain relief and side effects. The pharmacist is permitted to supply only three days' supply of pethidine or seven days' supply of morphine at any one occasion.

These pharmacies are inspected regularly. Opioid analgesics are available at pharmacies which have acquired a special permit to dispense what are called 'dangerous drugs'. They are called 'dangerous drugs' for good reasons.

Narcotic painkillers can kill

Opioids are otherwise known as narcotic analgesics. They are used as powerful painkillers. They include morphine, codeine, diamorphine (aka heroin), methadone, oxy-codone, pethidine and pentazocine. They produce pain relief, euphoria (feeling of well-being), a 'buzz', mental detachment and sedation (sleepiness).

The main problem is that repeated use of them (sometimes just over three days) may cause dependence and tolerance (needing more of the drug to produce the same effects). They are addictive and heavily abused, so using them does not always indicate that the user is having any physical pain.

My pharmacology teacher of 1988, in imparting to our class the side effects of hallucination and thought-disturbance of pentazocine, told us that "it could make us hear colours and see sounds!" Generally, side effects of these painkillers include nausea, vomiting, constipation, itching, difficulty urinating, drowsiness. More serious side effects include respiratory depression (slow, shallow breathing), slow heart rate and low blood pressure which may lead to cardiac arrest and death.

Propofol puts you to sleep

Interestingly, all the drugs including propofol for sleeping have the potential to cause apnoea (inability to breathe), hypotension and heart problems, which may be fatal.

Don't wanna be starting something

We await the toxicology report to determine which medications, if any, precipitated Michael's cardiac arrest. It's probably fair to say, however, that the King of Pop died of a broken heart.

Dahlia McDaniel is a pharmacist and final-year doctoral candidate in public health at the University of London; email: yourhealth@gleanerjm.com.