Re: Association between concurrent use of prescription opioids and benzodiazepines and overdose: retrospective analysis
It could be a life-threatening tragedy if the findings of a study involving many occasional, irregular and (in every sense) naïve US users of prescribed opiate analgesics were applied to patients in Methadone Maintenance Treatment (MMT) and other agonist maintenance programmes.
In the US and increasingly in other developed countries, opiates prescribed, wisely or not, for pain are being used increasingly as recreational drugs but in some important respects, these patients are very different from patients who have sought treatment for drug abuse and are established in MMT. The increased mortality of opiate users who abuse benzodiazepine (BDZ) drugs is well documented but the risk is largely determined by how they use their drugs rather than by straightforward drug interactions. When patients with little or no opiate tolerance take larger than normal amounts of their prescribed opiate, their risk of inadvertent death from opiate overdose is obviously increased and BDZs add to that risk. Their risk is also higher than for patients in MMT with relatively high tolerance, whose risk of inadvertent death from opiate overdose is thus greatly reduced.
Like poly-drug users in general, opiate users who seek licit or illicit BDZs are self-evidently a high-risk population because they tend to take more and bigger risks in many areas. They may take vast doses of BDZs and other drugs in a hedonistic and/or chaotic way and are more likely to inject drugs, share needles, have hepatitis C, abuse alcohol, and have unsafe sex . They also have more frequent contact with the police  than opiate users who do not abuse BDZs.
When chaotic heroin users engage with MMT, they typically become less chaotic and use less heroin, or none. It is increasingly argued that similar improvements might (and do) follow BDZ maintenance and for similar reasons. We have recently published persuasive evidence that in this challenging group, BDZ maintenance with diazepam or clonazepam, incorporated into daily dispensed and supervised MMT, improves treatment retention and lowers rather than raises mortality . More importantly, our findings strongly indicate that when patients appear to have responded favourably to BDZ maintenance, depriving them of it considerably increases mortality. It is likely to lead to more irresponsible use of BDZs that are now widely available via the internet without a prescription.
2. Darke S, Swift W, Hall W, et al (1993) HIV risk-taking and psychosocial correlates of benzodiazepine use among methadone maintenance clients. Drug and Alcohol Dependence 34(1):67-70
3. Loxley W (2007) Benzodiazepine use and harms among police detainees in Australia. Trends Issues Crime Criminal Justice. Canberra, ACT Australian Institute of Criminology p336
Competing interests: No competing interests