ATC Group: N07B Drugs used in addictive disorders

Acamprosate has a chemical structure similar to that of amino acid neuromediators, such as taurine or gamma-amino-butyric acid (GABA), including an acetylation to permit passage across the blood brain barrier. Acamprosate may act by stimulating GABAergic inhibitory neurotransmission and antagonising excitatory aminoacids, particularly glutamate. It is indicated as therapy to maintain abstinence in alcohol-dependent patients.

Buprenorphine is an opioid partial agonist/antagonist which attaches itself to the μ (mu) and κ (kappa) receptors of the brain. Its activity in opioid maintenance treatment is attributed to its slowly reversible link with the μ receptors which, over a prolonged period, minimises the need of illicit opioids for patients with opioid dependence.

Cytisine is a plant alkaloid with a chemical structure similar to nicotine. The use of cytisine allows for a gradual reduction of nicotine dependence by relieving withdrawal symptoms. The action of cytisine is similar to that of nicotine, but in general weaker. Cytisine competes with nicotine for the same receptors and gradually displaces nicotine due to its stronger binding.

Disulfiram is an inhibitor of numerous enzymes. Disulfiram is used to support the treatment of chronic alcoholism.

Levomethadone is a fully synthetic opioid analgesic which, as a basic diphenylmethane derivative, can be structurally derived from morphine. Bradycardia, hypotension, bronchoconstriction and antidiuresis are among the pharmacological effects of levomethadone, in addition to other classical opioid effects such as sedation, euphoria and miosis.

Lofexidine is a central alpha-2 adrenergic agonist that binds to receptors on adrenergic neurons. This reduces the release of norepinephrine and decreases sympathetic tone. It is used for mitigation of opioid withdrawal symptoms to facilitate abrupt opioid discontinuation in adults.

Methadone is a synthetic opioid analgesic similar to morphine although less sedative. It acts on the CNS system and smooth muscles via the peripheral nervous system.

Nalmefene is an opioid system modulator with a distinct μ, δ, and κ receptor profile. Nalmefene is indicated for the reduction of alcohol consumption in adult patients with alcohol dependence, without physical withdrawal symptoms and who do not require immediate detoxification.

Naltrexone is an orally used, long acting specific opioid antagonist. Naltrexone binds competitively to receptors which are located in the central and peripheral nervous system and hence blocks the access for exogenously administered opioids.

Nicotine, the primary alkaloid in tobacco products and a naturally occurring autonomous substance, is a nicotine receptor agonist in the peripheral and central nervous systems and has pronounced CNS and cardiovascular effects.

Varenicline binds with high affinity and selectivity at the α4β2 neuronal nicotinic acetylcholine receptors, where it acts as a partial agonist - a compound that has both agonist activity, with lower intrinsic efficacy than nicotine, and antagonist activities in the presence of nicotine.