Potency ratio of hydromorphone and diacetylmorphine in substitution treatment for long-term opioid dependency.

Author(s): Oviedo-Joekes E, Marsh DC, Guh D, Brissette S, Schechter MT.

Affiliation(s): School of Population and Public Health, University of British Columbia, Canada.

Publication date & source: 2011, J Opioid Manag. , 7(5):371-6

BACKGROUND: Data on conversion ratios for switching opioids in substitution treatment are limited. METHODS: Data were obtained from a randomized controlled trial among long-term opioid-dependent patients conducted in Vancouver and Montreal, Canada. Patients received diacetylmorphine (n = 115) or hydromorphone (n = 25) on a double-blind basis, on a 1:3 potency ratio with individually adjusted dosage, both injectable. RESULTS: Average daily dosages of hydromorphone and diacetylmorphine prescribed were 212.6 mg and 454.0 mg, respectively; potency ratio was 1:2.0-2.2 at different dose ranges. CONCLUSIONS: Studies using hydromorphone as a diacetylmorphine equivalent should consider the ratio found in this study to achieve equipotency and maintain the blinding.