Publication Highlights

Nicotine, cannabis and benzodiazepine have a potential for agonist maintenance treatment, according to an analysis conducted by NDARC Professors Shane Darke and Michael Farrell, published in the journal Addiction early online view in October.

Professors Darke and Farrell examined the feasibility of agonist maintenance treatment for the major psychoactive drug classes:

• Opioids,
• Nicotine,
• Benzodiazepines,
• Cannabis,
• Psychostimulants, and
• Alcohol.

Eight clinical criteria for an agonist maintenance drug, relating to pharmacological aspects of the drug (agonist, pharmacological stability, dose–response, non-toxic) and neurocognitive sequelae (psychiatric, cognitive, craving, salience) were assessed for each drug class.

Professors Darke and Farrell found that opioids and nicotine met all eight criteria for a maintenance drug, and while nicotine has not been promoted widely or used for maintenance, they note it had the potential to fulfil that role. Cannabis met five criteria and has potential, but long-term data on cognitive impairment are required.

The results also indicated that benzodiazepine maintenance would appear an option for the high-dose chaotic abuser, also meeting five criteria, although clinic dosing appeared the safest option.

Psychostimulants (three of eight criteria) and alcohol (one of eight) appeared poor propositions for maintenance, in terms of both their pharmacological and their neurocognitive characteristics.

Professors Darke and Farrell conclude that drug classes have properties that distinguish them in their suitability for maintenance treatment. They show that some classes not yet used for maintenance (notably nicotine and cannabis) have potential to fulfil such a role, whereas others, by their inherent nature, appear unsuitable for such a treatment regimen.