MEDICAL MATTERS: Misuse can result in poisoning and death
CHRONIC pain affects thousands of people in the Republic. With European prevalence levels approaching 20 per cent, moves are afoot to have pain redefined as a disease rather than a symptom.
About one in five people with chronic pain becomes depressed, while it is estimated that about 25 per cent lose their jobs as a result. Drug companies are busy researching new pain relieving agents, driven by greater scientific understanding of the condition.
Unsurprisingly, the prescription of painkillers, sedatives and other agents has shot up in response. But not without consequences, as a study in the current issue of the American Journal of Preventive Medicinehas found. Between 1999 and 2006, the number of people in the US taken to hospital for poisoning by prescription painkillers and tranquillisers increased by 65 per cent. The number of deaths from unintentional poisoning has been rising for about 15 years, including high-profile victims such as the actors Heath Ledger and Cory Haim.
So what is going on? It seems that in tandem with substantial increases in the total quantity of morphine-like painkillers being prescribed, there is a corresponding rise in the use of these drugs for recreational purposes. Significantly, between 2004 and 2006, while there has been a 44 per cent rise in emergency department attendances because of the misuse of prescription drugs, the US has experienced no increase in visits related to illegal drug use in the same three-year period.
“Deaths and hospitalisations associated with prescription drug misuse have reached epidemic proportions . . . prescription medications are just as powerful and dangerous as notorious street drugs, and we need to ensure people are aware of these dangers,” Dr Jeffrey Coben of the West Virginia University School of Medicine and lead study author says.
His data show the increasing role of opioids, sedatives and tranquillisers in both intentional and unintentional overdoses. Hospitalisations most frequently involved middle-aged women living in urban areas; the majority of cases were unintentional, although intent in a large number of cases was hard to assess. The drug associated with the largest percentage increase in hospitalisation for poisonings was methadone. A heroin substitute which forms the mainstay of drug treatment programmes in the Republic, the 400 per cent increase in poisonings with methadone revealed in this study is worrying. Especially when the increase for benzodiazepines (tranquillisers and sedatives) was 39 per cent and the number of poisonings caused by antidepressants actually dropped by 13 per cent.
Coincidentally, in its most recent Drug Safety Bulletin, the Irish Medicines Board (IMB) issued a warning to health professionals concerning the use of fentanyl transdermal patches. Marketed under trade names such as Durogesic and Fentanex, fentanyl is a potent opioid painkiller licensed for the treatment of cancer-related pain and also for chronic pain from other causes.
“Having reviewed global data, the IMB is aware of reports from other countries of life-threatening adverse reactions and death after fentanyl overdose in people who were using the patches to control malignant and non-malignant pain,” the agency said.
The factors it believed were related to unintentional overdoses with the patch, including dosing errors by patients and carers; accidental exposure to the patch, especially in children; and exposure of the patch to heat, which may result in increased absorption of fentanyl, above the dosage prescribed.
The IMB warnings reinforce the findings in the US study. Together they suggest a certain laxity among consumers in the use of powerful painkillers. Mixing these agents with alcohol, benzodiazepines and other drugs is dangerous; they can have a multiplicative effect. By depressing the breathing centre in the brain, recreational users face the real possibility of drifting off to sleep and never waking up.