Overdose suicides and prescription drugs

Overdose suicides are primarily due to the intake of prescription opioids and benzodiazepines, not illegal opioids.

Since the 1990s, the marketing and prescription of opioids in the United States has been widespread. Over time, opioids came to be regarded almost as harmless analgesics, and this led to an escalation in their use (1). The result was an 'epidemic' of opioid dependency and deaths, to an extent that we have not seen in Europe. But this does not mean that we are not affected by the same trends. Are we underestimating how dangerous opioids and other habit-forming medications are when we prescribe them? Are we overestimating the control we have through the Norwegian Prescription Database, e-prescriptions and universal health coverage?

The study by Nyman et al. published in this edition of the Journal of the Norwegian Medical Association shows that 94 per cent of all those who died by suicide from a drug overdose in the period 2016–21 had opioids in their blood (2). The study also shows that the main problem is not heroin and drugs used in opioid antagonist treatment but rather other prescription opioids. We cannot rule out the possibility that some of the drugs are bought and produced illegally, or sold illegally by someone selling their own prescription medicines. But we must acknowledge that many suicides by overdose in Norway appear to be carried out using medications prescribed to help the patient. Anti-depressants were also found in 43 percent of the deaths in this study – this may indicate treatment for depressive disorders where there is a known increased risk of suicide. But in most cases of overdose suicides, opiates and benzodiazepines are found in the blood, and much of this has probably also been prescribed by doctors: opiates primarily prescribed for pain relief, and benzodiazepines for anxiety and agitation and sometimes for sleep problems. Both of these drug categories are addictive. Antidotes exist for both, but people still die from their use.

But we must acknowledge that many suicides by overdose in Norway appear to be carried out using medications prescribed to help the patient

An earlier American study demonstrated that the prescription of benzodiazepines in particular increased the risk of suicide, even though opioids also increased the risk to some extent (3). We know that a considerable number of opioid users also use benzodiazepines (4). Many clinicians may assume that most patients would survive an overdose of zopiclone or diazepam. However, in combination with other medications, such as opioids and alcohol, they become dangerous. The clinical presentation of combined drug intoxication is unpredictable, and the drugs become more lethal than when taken alone. Nyman et al. show that drugs that are apparently non-lethal can be lethal in combination and in sufficiently large doses. This is particularly alarming in light of the findings from the United States (3) indicating that the use of benzodiazepines in particular increases the risk of suicide.

It is tempting to emphasise that the suicide figures in this study, as in other studies, are likely a minimum estimate. Are suicides concealed among overdoses classified as accidents? In a 2015 Scandinavian study, only 3 per cent of accidental poisonings were reclassified as suicide in an external re-evaluation (5). Hence, we can assume that the number of unreported cases was small. We will never obtain completely updated or definite answers but it is reassuring that forensic autopsies are performed in the case of more than 90 per cent of all overdose deaths in Norway (2). In doing so, we are providing the most accurate assessment of the cause of death. But why is this number not 100 per cent? It is important for the surviving family members that the reported cause of death is as accurate as possible. Moreover, it is important for our legal rights.

Full credit to the authors for linking data from forensic autopsies with data from the Norwegian Cause of Death Registry. The linkage of registry data and clinical data has provided new insights into overdose suicides and their association with drug prescription. Linking data to the Norwegian Prescription Database would give us the opportunity to investigate whether the drugs were obtained illegally or were prescribed for the patient here in Norway. In any case, we now know that to prevent overdose suicides, we must focus more on the prescriptions we write and not only on illegal opioids.