Treatment retention among patients randomized to buprenorphine/naloxone compared to methadone in a multi‐site trial

Abstract

Aims To examine patient and medication characteristics associated with retention and continued illicit opioid use in methadone (MET) versus buprenorphine/naloxone (BUP) treatment for opioid dependence. Design/Settings/Participants This secondary analysis included 1,267 opioid-dependent individuals participating in 9 opioid treatment programs between 2006 and 2009 and randomized to receive open-label BUP or MET for 24 weeks. Measurements The analyses included measures of patient characteristics at baseline (demographics; use of alcohol, cigarettes, and illicit drugs; self-rated mental and physical health), medication dose and urine drug screens during treatment, and treatment completion and days in treatment during the 24 week trial. Findings The treatment completion rate was 74% for MET vs. 46% for BUP (p<.01); the rate among MET participants increased to 80% when the maximum MET dose reached or exceeded 60mg/day. With BUP, the completion rate increased linearly with higher doses, reaching 60% with doses of 30–32mg/day. Of those remaining in treatment, positive opioid urine results were significantly lower (OR=0.63, 95%CI=0.52–0.76, p<.01) among BUP relative to MET participants during the first 9 weeks of treatment. Higher medication dose was related to lower opiate use, more so among BUP patients. A Cox proportional hazards model revealed factors associated with dropout: (1) BUP (vs. MET, HR=1.61, CI:1.20–2.15), (2) lower medication dose (<16mg for BUP, <60mg for MET; HR=3.09, CI:2.19–4.37), (3) the interaction of dose and treatment condition (those with higher BUP dose were 1.04 times more likely to drop out than those with lower MET dose, and (4) being younger, Hispanic, and using heroin or other substances during treatment. Conclusions Provision of methadone appears to be associated with better retention in treatment for opioid dependence than buprenorphine, as does use of provision of higher doses of both medications. Provision of buprenorphine is associated with lower continued use of illicit opioids.

Report on the first government-funded opioid substitution programme for heroin users in the Western Cape Province, South Africa

“…[19] The only other evaluation of an OST programme in Africa reported a retention rate of 57% over 2 years, [20] although it utilised methadone, which differs from buprenorphine with regard to retention. [17] The rate for the OST group in our study was therefore relatively high. Even among participants who did not complete treatment, those in the OST programme remained on average 18 days longer (p=0.001) than in the standard group.…”

“…Retention rates in treatment reported in the literature vary widely, but it is generally estimated that >50% of patients leave or are withdrawn in the first 3 weeks of treatment. [12][13][14] After 6 months of treatment, one study reported retention of 79%, [15] but others noted much lower rates of 58%, [16] 46% [17] and 27%. [18] In another study, an average of only 44% of buprenorphine clients spent at least 3 weeks in an Australian treatment facility.…”

“…[21][22] While this may reflect international experience that longer periods than the SBRC's 12-week programme are necessary for higher abstinence, a possible reason for the low rate could be the high rate (54.8%) of concomitant use of other potentially destabilising drugs, which often leads to impulsive use of heroin during rehabilitation. [17] In addition, so that more participants could be included in a setting where funding was limited, a lower dose of the opiate analogue was used (median 4 mg) than that required to suppress illicit opioid use. While any dose above 2 mg retains participants in treatment, at least 16 mg is necessary to suppress illicit opioid use.…”

The impact of buprenorphine and methadone on mortality: a primary care cohort study in the United Kingdom

“…In a recent US randomized controlled trial, patients with opioid dependence who received buprenorphine had a shorter duration of treatment and were more likely to drop out than those receiving methadone 34. This association has been reported by systematic reviews 19, 35.…”

“…that treatment duration is shorter) 19, 34, 37. Long‐term follow‐up of trial participants reported no differences in drug outcomes for patients randomized to buprenorphine or methadone, but was underpowered to detect differences in mortality 55.…”