Varenicline is a partial nicotinic acetylcholine receptor agonist, designed to partially activate this system while displacing nicotine at its sites of action in the brain. Varenicline is an alpha-4 beta-2 neuronal nicotinic acetylcholine receptor partial agonist. The drug shows high selectiviyty for this receptor subclass, relative to other nicotinic receptors (>500-fold alpha-3 beta-4, >3500-fold alpha-7, >20,000-fold alpha-1 beta gamma delta) or non-nicotinic receptors and transporters (>2000-fold). The drug competitively inhibits the ability of nicotine to bind to and activate the alpha-4 beta-2 receptor. The drug exerts mild agonistic activity at this site, though at a level much lower than nicotine; it is presumed that this activation eases withdrawal symptoms. Varenicline is sold under the trade name Chantix and Champix, it is indicated for use as an aid to smoking cessation treatment.

Bupropion, an antidepressant of the aminoketone class and a non-nicotine aid to smoking cessation, is chemically unrelated to tricyclic, tetracyclic, selective serotonin re-uptake inhibitor, or other known antidepressant agents. Compared to classical tricyclic antidepressants, Bupropion is a relatively weak inhibitor of the neuronal uptake of norepinephrine, serotonin, and dopamine. In addition, Bupropion does not inhibit monoamine oxidase. Bupropion produces dose-related central nervous system (CNS) stimulant effects in animals, as evidenced by increased locomotor activity, increased rates of responding in various schedule-controlled operant behavior tasks, and, at high doses, induction of mild stereotyped behavior. Bupropion is marketed as Wellbutrin, Zyban, and generics. Bupropion is indicated for the treatment of major depressive disorder (MDD). WELLBUTRIN, WELLBUTRIN SR, and WELLBUTRIN XL are not approved for smoking cessation treatment, but bupropion under the name ZYBAN is approved for this use.

Nicotine is a natural alkaloid obtained from the dried leaves and stems of the nightshade family of pants, such as Nicotiana tabacum and Nicotiana rustica, where it occurs in concentrations of 0.5-8%. Cigarette tobacco varies in its nicotine content, but common blends contain 15-25 mg per cigarette, with a current trend towards lower levels. Nicotine is highly addictive substance, it exhibits a stimulant effect when adsorbed at 2 mg. Administration of higher doses could be harmful. Action of nicotine is mediated by nicotinic cholinergic receptors. Nicotine binds to the interface between two subunits of the receptors, opens the channel and allows the entry of sodium or calcium. The principal mediator of nicotine dependence is α4β2 nicotine receptor.

Pozanicline is an alpha4-beta2 neuronal nicotinic receptor partial agonist. It had been in phase II clinical trials for the treatment of attention hyperactivity disorder and Alzheimer’s disease. It was tested for the treatment of schizophrenia too. All these studies were discontinued. Modulation of hippocampal learning and memory using Pozanicline in animal model was effective as novel therapeutic strategies for nicotine addiction. However future clinical trial was terminated.

Ro 32-0432 hydrochloride is an orally available cell-permeable selective inhibitor of PKC enzymes. Moreover, Ro 32-0432 inhibits G protein-coupled receptor kinase 5 activity. Ro 32-0432 prevents T cell-driven chronic inflammatory responses in several rat models. Ro 32-0432 inhibits an antigen-driven T-cell-mediated arthritis in vivo. Treatment of rats with Ro 32-0432 in ischemic stroke decreases the ischemic infarction area, neurological symptoms and associated endothelin B receptor upregulation. Ro 32-0432 attenuates the propagation of nicotine dependence and reduce withdrawal signs possibly by G protein-coupled receptor kinase 5 activation-linked mechanisms.

Sazetidine-A (6-[5-(azetidin-2-ylmethoxy)pyridin-3-yl]hex-5-yn-1-ol or AMOP-H-OH) is a "silent desensitizer" of neuronal nicotinic acetylcholine receptors (nAChRs), meaning that it desensitizes the receptor without first activating it. Later it was shown that Sazetidine-A is an agonist of native and recombinant alpha4beta2 nAChRs but shows differential efficacy on alpha4beta2 nAChRs subtypes. In animal models it is able to regulate the gain in body weight, alcohol and nicotine dependence. Sazetidine-A exerts analgesic, antidepressant and anxiolytic properties.

Anabasine, a tobacco alkaloid, was used as a biomarker of active tobacco use. Anabasine is a selective alpha7-nicotinic acetylcholine receptor agonist. Anabasine antagonized MK-801-elicited mouse popping behavior, an animal model of schizophrenia.

Cotinine is a product formed after the chemical nicotine enters the body. Measuring cotinine in people’s blood is the most reliable way to determine exposure to nicotine for both smokers and nonsmokers exposed to environmental tobacco smoke. Cotinine is safe, non-addictive and has pharmacokinetic properties adequate for therapeutic use. Research has shown that cotinine has antipsychotic, anxiolytic, and antidepressant properties and modulates the serotonergic, cholinergic and dopaminergic systems. Cotinine behaves as a positive allosteric modulator of the nicotinic acetylcholine receptors and has anti-inflammatory effects. Cotinine is under investigation as an agent for the treatment of depression, PTSD, schizophrenia, Alzheimer's disease and Parkinson's disease.

Varenicline is a partial nicotinic acetylcholine receptor agonist, designed to partially activate this system while displacing nicotine at its sites of action in the brain. Varenicline is an alpha-4 beta-2 neuronal nicotinic acetylcholine receptor partial agonist. The drug shows high selectiviyty for this receptor subclass, relative to other nicotinic receptors (>500-fold alpha-3 beta-4, >3500-fold alpha-7, >20,000-fold alpha-1 beta gamma delta) or non-nicotinic receptors and transporters (>2000-fold). The drug competitively inhibits the ability of nicotine to bind to and activate the alpha-4 beta-2 receptor. The drug exerts mild agonistic activity at this site, though at a level much lower than nicotine; it is presumed that this activation eases withdrawal symptoms. Varenicline is sold under the trade name Chantix and Champix, it is indicated for use as an aid to smoking cessation treatment.

Varenicline is a partial nicotinic acetylcholine receptor agonist, designed to partially activate this system while displacing nicotine at its sites of action in the brain. Varenicline is an alpha-4 beta-2 neuronal nicotinic acetylcholine receptor partial agonist. The drug shows high selectiviyty for this receptor subclass, relative to other nicotinic receptors (>500-fold alpha-3 beta-4, >3500-fold alpha-7, >20,000-fold alpha-1 beta gamma delta) or non-nicotinic receptors and transporters (>2000-fold). The drug competitively inhibits the ability of nicotine to bind to and activate the alpha-4 beta-2 receptor. The drug exerts mild agonistic activity at this site, though at a level much lower than nicotine; it is presumed that this activation eases withdrawal symptoms. Varenicline is sold under the trade name Chantix and Champix, it is indicated for use as an aid to smoking cessation treatment.