Time-Course of Buprenorphine Dose Increase in a Maintenance Program for Heroin Addicts: Retention in Treatment and Clinical Meaning

Buprenorphine is a major therapeutic option in the treatment of opiate addiction. Peculiarly, increasing dosages do not grant higher and higher levels of agonism, but a plateau is soon reached due to it’s the high affinity to the μ-receptor (ceiling effect). In terms of anticraving action, the ceiling level of agonism seemsto be equivalent to that provided by 80 mg of methadone. Differently from methadone, subjects with residual craving are challenged with strong opiate blockade, due to buprenorphine’s slow dissociation from receptors at high dosages, which may either cause treatment dropout or stabilisation, according to the strength of residual craving. 

In fact, early attrition in buprenorphine programs seems to be related to withdrawal buffering, and does not vary according to dosage, due to limited agonist potency. On the other hand, for those who stay in treatment at anti-withdrawal dosages, higher dosages grant with better outcomes in fixed dose comparison studies. However, it is notsharply clear whether the gap of effectiveness is mainly related to a higherlevel of agonism or the opioid blockade: In fact, some patients do respond to 2-4-6 mg regimens by a significant rate.