TORONTO – Whether they had relapsed in the first 2 weeks strongly predicted a successful long-term outcome in patients with prescription opioid dependence undergoing treatment with buprenorphine-naloxone, according to findings presented at the annual meeting of the American Psychiatric Association.
“People either need to hit the ground running and do well quickly, or you need to cage something within a couple of weeks,” said Dr. Roger D. Weiss, chief of the division of alcohol and drug abuse at McLean Hospital in Belmont, Mass. The typical time course of response to buprenorphine-naloxone in the treatment of prescription opioid dependence is not known, and given the overall studies’ fairly poor success rate (<10% at completion), knowing this information could help guide clinical practice in the treatment of this population, Dr. Weiss said.
Most studies of buprenorphine have focused on heroin users, who differ from prescription opioid users on socioeconomic and compliance measures.
The researchers looked at both positive predictive value – the degree to which initial opioid abstinence predicted final successful outcome at the end of 12 weeks, along with negative predictive value – the degree to which initial opioid use predicted final unsuccessful outcome.
“So, does getting off to a good start predict a good outcome and does getting off to a bad start predict a bad outcome?” Dr. Weiss asked.
Turns out, that if people were abstinent in week 1, the likelihood they would be absent at weeks 9-12 was 49%, “essentially a coin flip,” he said. If abstinence were maintained for the first 2 weeks, the PPV went up to 56%, rising a few more points out to week 4.
“Two weeks gave you as good a prediction as you’re going to get, but it’s not a great prediction,” explained Dr. Weiss, also a professor of psychiatry at Harvard Medical School in Boston.
However, looking at the negative predictive value offered more information. If the patients used opioids in week 1, the likelihood of a bad outcome was 80%, and this rose to 94% if they used in the first 2 weeks and 97% if they used in the first 4 weeks.
“So if they don’t do well in 2 weeks, the likelihood that, if you just wait a little while, they’ll do better, was almost nil,” Dr. Weiss said.
The Prescription Opioid Addiction Treatment Study (POATS) compared treatments for prescription opioid dependence, using buprenorphine-naloxone of different durations and counseling of varying intensities. The trial was conducted as part of the National Institute on Drug Abuse Clinical Trials Network (NIDA CTN) at 10 participating sites across the United States.
With 653 patients, POATS was the largest study ever conducted for prescription opioid dependence and sought to determine the value of added drug counseling to buprenorphine-naloxone treatment, and determine the optimal length of buprenorphine-naloxone treatment for these particular patients. To be eligible for enrollment, patients had to have a DSM-IV diagnosis of opioid dependence, not just physical dependence.
In POATS, patients began with 1-2 weeks of buprenorphine-naloxone treatment followed by a 4-week taper and were then randomly assigned to regular or more intensive drug counseling.
Patients who had a successful outcome in phase 1 (defined as 4 days or fewer of use per month, no positive urine screens for 2 consecutive weeks, no injection of opioids, no other formal substance abuse treatment, and not more than one missing urine sample) were considered finished with the study.
Those who relapsed had the option of going to phase 2, where they received 3 months of buprenorphine-naloxone stabilization and were rerandomized to standard care or standard care plus extra drug counseling. They also received 12 weeks of buprenorphine-naloxone treatment, followed by a taper period until week 16.
Dr. Weiss disclosed that he has consulted to Reckitt Benckiser Pharmaceuticals, maker of the drug, but vowed to “present the content in a fair and balanced manner.”