24 August 2016 14:37:39

Prince, pain and the counterfeit drug conundrum

Only after his death did we hear about the crippling joint pain that had blighted so much of Prince's life. And only now has it come to light that he may have died of an accidental overdose after taking counterfeit painkillers.

I grew up on 'When Doves Cry'. Purple Rain was the soundtrack to my youth - so I was as shocked as any to hear of Prince's death at the age of 57. Only after his death did we hear about the crippling joint pain that had blighted so much of his life. And only now has it come to light that he may have died of an accidental overdose after taking counterfeit painkillers.

Obviously I'm not privy to the police investigation, so I'm only going on what's in the public arena. But what news there has been is very worrying. Drugs found in his home included bottles labelled "Watson 385", a US painkiller brand containing acetaminophen (called paracetamol in the UK) and hydrocodone, a product made from codeine. Yet he was found to have died from an overdose of fentanyl - a painkiller at least 100 times as strong as morphine gram for gram - and the counterfeit "Watson 385" tablets contained both fentanyl and the anaesthetic lidocaine.

The most common reason I prescribe either morphine or fentanyl is for terminally ill patients. Doctors use 'opioid conversion charts' to make sure that when they switch from one to another, they're giving approximately the same dose in terms of pain relief. Hydrocodone is weaker than morphine - fentanyl is many times stronger.

I most commonly prescribe fentanyl in the form of patches applied to the skin, which release a steady dose of pain relief. The dose of these patches is measured in micrograms - millionths of a gram. Morphine is measured in milligrams, and there are 1000 micrograms in a milligram. The conversion dose for a fentanyl patch giving 2.4 milligrams of fentanyl in 24 hours is 315-404 milligrams of morphine. For fentanyl given as a continuous dose via a needle under the skin, the conversion rate is 150 to 1.

Disguising counterfeit drugs containing strong opioids like fentanyl as weaker tablets would be an obvious way to bypass customs. Most pharmacies will get their supplies from reputable sources - but buying drugs from the internet is a completely different story.

The World Health Organization estimates that 1% of drugs in developed countries, and up to 10% of drugs globally, are counterfeit. Just two years ago, the UK drug regulating agency, the Medicines and Healthcare products Regulatory Authority (MHRA), seized millions of pounds' worth of counterfeit medicines. When they were analysed, ingredients included banned medicines, blue paint and rat poison. They were recovered from filthy buildings with broken windows and vermin roaming around. But the drugs themselves were professionally and convincingly packaged - it's a multi-billion dollar industry.

In theory, Prince may have known the drugs he took were counterfeit. But even if he did, he's highly unlikely to have realised the risks. No drug is licensed without a full assessment of its risks and benefits. On the whole, the more powerful the drug, the higher the level of side effects - and the more cautiously it's used by doctors.

Fentanyl gives a very fast 'high' to recreational users because it's so quickly absorbed into the system. It's also completely synthetic, which makes it easy to manufacture in large quantities. But at high doses, fentanyl (like all opioids) can suppress breathing - and that too happens with frightening speed. Use it in combination with other opioids like hydrocodone and the risk rises. Lidocaine can cause irregular heart rhythms or even cause the heart to stop. A combination of the two is a disaster waiting to happen.

We may never know the truth about what happened that night at Paisley Park. We do know an extraordinary man was cut down well before his time. We also know that counterfeit medicines may have played a part. And if it can happen to Prince, it can happen to anyone. It may not be the legacy he wanted, but I'd like to hope that it makes anyone who's tempted stop and think. Counterfeit drug manufacturers only have one person's interest at heart - and it's most definitely not the 'patient'.

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.