Overdose from prescription opioids (e.g., Oxycodone, Hydrocodone) has become one of the most common causes of accidental death in the United States. Two new articles in BMJ suggest that overdose is not the only risk about which patients, prescribers and policy makers should be concerned.
Khademi and colleagues conducted a prospective study of a cohort of 50,045 Iranians. They followed up over 99% of the sample and then assessed the impact of opium use on mortality. After statistically adjusting for cigarette smoking, education, age and other factors, the research team reported that opium use nearly doubled the risk of death. The number of diseases with increased incidence among opium users was large, and included tuberculosis, cancer, and chronic obstructive pulmonary disease. The results held even when the researchers excluded from analysis individuals who started using opium in response to the onset of a chronic illness.
These results do not necessarily generalize to prescription painkillers such as Oxycontin. Unlike opium, which comes directly from the poppy flower, modern, synthetic opioids are free of impurities are not prescribed in a smoked form. Further, opium use in Iran may be a marker for other risk factors (e.g., poor self-care habits, social isolation) for which the epidemiological study could not fully adjust.
That said, in an accompanying commentary in BMJ, Dhalla notes that preliminary studies have found indications of higher death rates in patients with the same medical condition who take opioid medications versus non-steroidal anti-inflammatory drugs. The higher mortality risk is not simply attributable to accidental overdoses. None of these studies of prescription opioids is definitive, but they certainly justify a larger replication research effort along the lines of the Iranian study of opium users.
The worrisome fact about prescription opioids is that their use has grown extraordinarily rapidly in a short period in the United States, to over 200 million prescriptions in 2010 alone. As a result, any adverse impacts of opioids that take a few years to accrue may hit the population in a tidal wave before there is time to understand and prevent the damage.
Cross-posted at Stanford Medical School’s SCOPE Blog.