HARCP Archives

Browse by article

Browse by volume

Heroin Addiction and Related Clinical Problems: 2010, 12, 4 (pages: 41 - 48)

Treating heroin addicts. Blocking dosages and stimulation-stabilization of opioidergic system

Pacini M., Maremmani A. G. I., Rovai L., Rugani F., Maremmani I.

Summary: The paper that follows is an attempt to conceptualize a clinically based classification of treatments for heroin addiction. In fact, a distinction is drawn in classifying treatments between those that are antagonists and those that are agonists; the latter can be further subdivided into full and partial. On this view, the effectiveness of full agonists cannot be displayed as dependent on a key antagonist action, originally described as an ‘opioid blockade' and regarded as the main therapeutic mechanism available against addiction. On the other hand, the differences in levels of effectiveness between antagonists and full agonists cannot be understood either in terms of the presence of absence of antagonism, or as opposing two radically different mechanisms of action (it remains true that they both produce an opioid blockade). In proceeding further, the authors propose the concept of optimal antagonism, which is centred around the original ‘opioid blockade' mechanism and also accounts for agonist potency providing a direct anticraving effect and aversive effects. Also, acquired tolerance to opiates does function as a drawback deriving from abrupt treatment termination or steep reduction, so as to favour stability of the anticraving coverage. In practice, optimal antagonism is a concept that helps to define the gold standard of retention, clinical response and rehabilitative potential. Naltrexone only provides patients with antagonism, which does not appear to be the crucial feature of the ‘narcotic blockade' originally described for full agonists, since levels of global effectiveness differ markedly. The balance between the level of narcotic blockade and other properties corresponds to the level of global effectiveness of a treatment regimen, which eventually explains why complete blockade brings poorer results in the absence of other anticraving actions. Methadone and buprenorphine appear to provide optimal antagonism; in other words, they offer patients opioid blockade combined with tolerance to euphoria and direct anticraving action.