|SAMHSA: National Survey on Drug Use and Health, 2008|
In most news stories about prescription opioids or heroin, the drugs are usually described as "highly addictive." Heroin in particular is considered among the most addictive, supposedly immensely pleasurable and causing an insatiable craving for more. And yet according to data collected by SAMHSA, only 13.4% of people who first try heroin are dependent on the drug one year later. For "non-medical" users of prescription opioids, the number is only 3.1%. Interesting, based on the SAMHSA data, marijuana is almost twice as addictive as oxycodone.
One may wonder why heroin users become dependent at a rate more than four times that of pharmaceutical opioid users. This may be explained in part due to the heroin shift, users of pharmaceutical opioids switching to heroin following the nationwide crackdown on "pill mills." Secondly heroin is so demonized that that those who use it are a self-selected population. Compared to cannabis or cocaine, there just aren't as many recreational heroin users out there (people who might get high occasionally on weekends or special occasions).
Defenders of the drug war claim that drug prohibition is the only thing holding back legions of potential addicts. The truth is that the response to opioids is highly individualized, many people experience only negative effects (nausea and headaches are common) and no euphoria.
The Prescription Painkiller Experience: Less than a Third Say They Like It
by Maia Szalavitz
Many people fear that mere exposure to prescription painkillers like Vicodin or OxyContin will set them down the road to addiction. But new research on the response to opioid medication suggests that most people don’t particularly like the experience of using the drugs — a key factor in future addiction risk.
Researchers led by Dr. Martin Angst of Stanford University studied 114 pairs of identical twins aged 18 to 70, none of whom had chronic pain or addiction. Participants received intravenous infusions of either placebo or the opioid alfentanil, a drug that is approximately 10 times stronger than heroin and is used as an anesthetic during surgery. IVs are known to be the most addictive route of drug administration.
According to the findings, published in the journal Anesthesiology, 14% of participants said they disliked the opioid experience outright. About 6% found it neither pleasant nor unpleasant and 52% had mixed feelings about it; 23% of those with mixed feelings said they disliked it more than they liked it. Less than one-third (29%) of volunteers said they liked the opioid experience unreservedly. “If you would split it up, you would say about a quarter really didn’t like it and a quarter really liked it a lot,” says Angst, a professor of anesthesia at Stanford.
Researchers study drug liking as a sign of addiction risk; not surprisingly, people do not usually become addicted to drugs they don’t like. But liking alone doesn’t necessarily lead to addiction; otherwise addiction rates would be at least double what they appear to be now: research on recreational use of heroin finds, for example, that 69% of those who try the drug are not using it at all a year later, while 13% are addicted. For prescription opioids, 57% who try the drugs non-medically aren’t using them a year later; 3% are addicted.
Meanwhile, another new study published in the journal Addiction [see results and link below- Ed] reviewed the literature on addiction risk following exposure to opioid medication for pain. The data on the subject are not very strong, the review suggests, but they do show a wide range of risk: anywhere from 0% to 24% of people treated for chronic pain or cancer pain can expect to develop a new addiction. However, the average risk found in the data is less than half a percent, meaning that the studies showing extremely high percentages represent outliers.
“We have an immense problem because we don’t understand who is at risk and under what circumstances,” says Clark in reference to the rates of prescription painkiller overdose and addiction, which have been skyrocketing in recent year.
Numerous studies have been done which look at the rate of addiction in patients treated with opioids for chronic pain. Cited below are two reviews, one done by the prestigious Cochrane Review, found that iatrogenic addiction was rare, occurring in less than 1% of the patients. A more recent review published in Addiction found an average rate of 0.5% (though some studies did have unusually high numbers, up to 24%). Both studies concluded that iatrogenic addiction was rare in patients treated for chronic pain.
The irony behind this is that there exists in the public mind two groups of people who consume opioids: "legitimate" pain patients and "illegitimate" addicts. And yet the most evidence-based treatment for opioid addiction is to prescribe an opioid, usually methadone or buprenorphine, and rarely heroin. The major difference in treatment is that the addict's access to the drug is far more restricted, and there are additional requirements involving some form of psycho-social support . The result is a massive medical bureaucracy around the dispensing of narcotics, pain clinics on one end and methadone clinics on the other. Drug testing industries profit from both systems, monitoring the patients for any use of the naughty substances (but never tobacco, which has a higher burden of disease and death than all illegal drugs combined). All of this over a substance that grows naturally from the ground and has been legally traded for most of human history!
Long-term opioid management for chronic noncancer pain
The Cochrane Library
Published Online: 20 JAN 2010
We reviewed 26 studies with 27 treatment groups that enrolled a total of 4893 participants. Twenty five of the studies were case series or uncontrolled long-term trial continuations, the other was an RCT comparing two opioids. Opioids were administered orally (number of study treatments groups [abbreviated as "k"] = 12, n = 3040), transdermally (k = 5, n = 1628), or intrathecally (k = 10, n = 231). Many participants discontinued due to adverse effects (oral: 22.9% [95% confidence interval (CI): 15.3% to 32.8%]; transdermal: 12.1% [95% CI: 4.9% to 27.0%]; intrathecal: 8.9% [95% CI: 4.0% to 26.1%]); or insufficient pain relief (oral: 10.3% [95% CI: 7.6% to 13.9%]; intrathecal: 7.6% [95% CI: 3.7% to 14.8%]; transdermal: 5.8% [95% CI: 4.2% to 7.9%]). Signs of opioid addiction were reported in 0.27% of participants in the studies that reported that outcome. All three modes of administration were associated with clinically significant reductions in pain, but the amount of pain relief varied among studies. Findings regarding quality of life and functional status were inconclusive due to an insufficient quantity of evidence for oral administration studies and inconclusive statistical findings for transdermal and intrathecal administration studies.
Many patients discontinue long-term opioid therapy (especially oral opioids) due to adverse events or insufficient pain relief; however, weak evidence suggests that patients who are able to continue opioids long-term experience clinically significant pain relief. Whether quality of life or functioning improves is inconclusive. Many minor adverse events (like nausea and headache) occurred, but serious adverse events, including iatrogenic opioid addiction, were rare.
Development of dependence following treatment with opioid analgesics for pain relief: a systematic review
Addiction. Volume 108, Issue 4, pages 688–698, April 2013
Data were extracted from 17 studies involving a total of 88 235 participants. The studies included three systematic reviews, one randomized controlled trial, eight cross-sectional studies and four uncontrolled case series. Most studies included adult patients with chronic non-malignant pain; two also included patients with cancer pain; only one included patients with a previous history of dependence. Incidence ranged from 0 to 24% (median 0.5%); prevalence ranged from 0 to 31% (median 4.5%).
The available evidence suggests that opioid analgesics for chronic pain conditions are not associated with a major risk for developing dependence.