Observing Opioids: How the Risk of Addiction Grows Over Time

Overview of the Opioid Epidemic

Opioids are substances that bind to the nervous and gastrointestinal systems, numbing pain and causing a feeling of euphoria. Since the late 1990s, doctors in the United States have prescribed opioid products for growing number of patients with chronic pain. Pharmaceutical companies have simultaneously developed stronger opioids.
Because they are chemically similar to heroin, opioid products have a high risk of dependence. Long-term users also develop opioid tolerance, meaning they need more of the drug to achieve the same effect and satisfy their dependence. As a result, users often start taking opioids in unsafe quantities, raising the risk of overdose. When patients’ opioid prescriptions run out, they often switch to heroin, providing the same effect at a lower cost.
As a result of this process, opioid and heroin use have grown dramatically in recent decades. Every day, 3,900 Americans begin using opioids for non-medical purposes, and 580 begin taking heroin. This leads to nearly 30,000 deaths and $55 billion in social and health costs per year in the United States alone.
American health authorities are struggling to stop this deadly trend. While some recommend phasing out opioids in favor of safer alternatives, doctors have the potential to moderate this crisis by changing how they prescribe existing painkillers. A recent study by the CDC, “Characteristics of Initial Prescription Episodes and Likelihood of Long-Term Opioid Use,” explores how current prescription practices affect the probability of addiction. Armed with this study, doctors can prescribe opioids in a way that dramatically reduces the risk of addiction.

Study Specifics

Using records from the IMS Lifelink+ database, researchers sampled 10 percent of patients treated between 2006 and 2015. They then narrowed these records down to opioid naïve patients, or patients who had never previously taken opioids, who were given at least one day’s supply of opioids during the period. This produced a sample of 1,294,247 patients. The records contained detailed information on patient background, treatment details, and the length of opioid use after treatment. The researchers then used Kaplan-Meier statistical methods to calculate:

The median time it took patients to stop using opioids

The probability that patients would continue using opioids after 1 and 3 years, given the duration of treatment

The number of prescriptions each patient received

The dose patients received the first time they used opioids

The link between the choice of opioid, the size of the supply provided, and the likelihood that a patient would keep using opioids after 1 and 3 years

In addition to these estimates, the researchers performed sensitivity analyses to see how excluding patients who received particularly high doses, changing the discontinuation definition, and altering the permissible gap in the first opioid use episode affected the results. This ensured that the results would be robust.

Research Results

The researchers found that the overall probability of opioid addiction was low, with only six percent of those receiving an opioid prescription for at least a day continuing to use the drug after 1 year. The likelihood of addiction grew dramatically over time, however. Of those who received treatment for more than 7 days, 13.5 percent continued using opioids after a year; for treatments exceeding one month, 29.9 percent used the drug after a year. The risk of addiction continued to climb until treatment length reached 12 weeks, at which point it leveled off.
In addition to length of treatment, the likelihood of addiction was also influenced by the size of the initial dose. Patients who received a dose between 400 and 799 morphine milligram equivalents were three times as likely to become chronic users than those who received less than 120. Likewise, patients who were prescribed two refills were 2.3 times as likely to become addicted than those prescribed only one. Tramadol was associated with a higher risk of addiction than other opioid products.
The study thus provides a clear roadmap for physicians. Doctors who deem opioids necessary should prescribe the minimum dosage for as short a period as possible to be effective, and should avoid prescribing tramadol. They can thus reduce the risk of addiction even if alternatives to opioids do not become available.
For more information on preventing and treating opioid addiction, contact the Opiate Treatment Center today.