Buprenorphine

There is increasing evidence for the effectiveness of buprenorphine (Subutex® or Suboxone®) as a substitute medication. Buprenorphine is a synthetic mixed agonist-antagonist medication and not a pure but a partial opioid agonist. Its effectiveness seems comparable to methadone. Although it has not proven to be more effective than methadone, some individuals benefit from this partial agonist-antagonist. The opioid effects of this medication are limited and thus buprenorphine is less likely to produce overdose. Some countries have made buprenorphine more available than methadone, which in part may be based on overcoming resistance to providing substitution treatment. In France for example, the majority of substitution treatment is provided with buprenorphine. In 2000, there were only 5000 people receiving methadone in France against an estimated group of 80.000 receiving buprenorphine. In Austria, 35% of patients receiving substitution treatment receive buprenorphine; compared to 5% in Portugal and 15% in Germany. Buprenorphine has been introduced in office-based medicine in Australia in 2000, and in the United States in October 2002.

Some experts prefer buprenorphine for younger drug users and methadone for older users on a long-term basis. Buprenorphine also seems better for pregnant women, because it causes fewer neonatal problems than methadone. On the other hand, methadone is easily administered and cheap, around €8,- per person per week, compared with € 65,- for buprenorphine (EMCDDA, 2002).

Buprenorphine was developed as a strong analgesic, as strong as morphine, but with less toxicity. It is a partial agonist - antagonist. Because of its partly antagonist character buprenorphine produces less distinct side effects of euphoria, constipation, sweating and numbing. Clinical data show that seriously diminished breathing may be less of a risk with buprenorphine than with other opioids when taken in high doses or in overdose situations. However, buprenorphine has been linked to deaths caused by diminished breathing, especially if used with alcohol or depressants, according to reports from France, where the drug was first approved in 1996. Since then, 24 countries have approved buprenorphine for opioid addiction.
Buprenorphine is a partial opiate agonist with high affinity for opiate receptors:
* Opiate-like effects and side-effects
* Prevents withdrawal
* Reduces craving
* Reduces effects of other opiates
* More difficult to overdose on than other opiates
* Long duration of action
* Mild withdrawal profile
* Sublingual tablet preparations (which is soluble in saliva and water, therefore injectable)

Research has not identified whether certain types of clients respond better to buprenorphine or methadone.
The choice between methadone and buprenorphine depends upon:
* Logistics of participating in treatment
* Response to treatment
* Individual variation in absorption, metabolism, clearance of medication
* Side effects
* Ease of withdrawal from medication
* Client (and clinician) expectancy
* Ability to transfer from methadone

More information about buprenorphine can be found in the Euro-Methwork publication Buprenorphine, critical questions examined