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[Pharmacology](https://durgical.com/en/pharmacology/) · Class

# Smoking cessation medicines

Medicines that ease craving and withdrawal when quitting tobacco: nicotine replacement, varenicline, cytisine and bupropion. They work best with support.

Updated 2026-11-01

## What they are

WHO's 2024 guideline names varenicline, nicotine replacement therapy, bupropion and cytisine as effective treatments for quitting tobacco, combined with behavioural support. More than 60% of the world's tobacco users want to quit.

## Mechanism of action

Nicotine replacement gives nicotine without smoke, at steadier levels, to soften withdrawal. Varenicline and cytisine are partial agonists at α4β2 nicotinic receptors: they partly stimulate them, easing craving, and block nicotine from binding, so smoking gives less reward.

Target: α4β2 nicotinic acetylcholine receptor

## Key points

- Partial agonist = less craving (partial stimulation) plus less reward from smoking (blocks nicotine).
- Varenicline is cleared almost unchanged by the kidneys: its dose is adjusted in severe kidney impairment.
- Quitting smoking can change the effects of theophylline, warfarin and insulin, whichever medicine is used.
- Used nicotine patches still hold enough nicotine to poison children and pets.

## Drugs in this class

- [**Varenicline** A nicotinic receptor partial agonist that eases craving and makes smoking less rewarding. Nausea and vivid dreams are… Nicotinic acetylcholine receptor α4β2](https://durgical.com/en/pharmacology/varenicline/)
- [**Nicotine (replacement therapy)** Nicotine without the smoke, as patches, gum, lozenges or sprays, to ease craving and withdrawal while quitting tobacco. Nicotinic acetylcholine receptor α4β2](https://durgical.com/en/pharmacology/nicotine/)
- [**Cytisine** A plant alkaloid that is a nicotinic partial agonist, used to quit smoking. WHO added it to the essential medicines… Nicotinic acetylcholine receptor α4β2](https://durgical.com/en/pharmacology/cytisine/)

## Others in the class

- Bupropion

## Test yourself

Think of the answer, then tap the question to see it.

## Which four medicines does WHO name for quitting tobacco?

Varenicline, nicotine replacement therapy, bupropion and cytisine.

## What are the two effects of a nicotinic partial agonist in smoking cessation?

It eases craving by partial stimulation and reduces the reward of smoking by blocking nicotine.

## Why may theophylline or warfarin need review when someone quits smoking?

Quitting smoking itself can change how these drugs act.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [WHO releases first-ever clinical treatment guideline for tobacco cessation in adults](https://www.who.int/news/item/02-07-2024-who-releases-first-ever-clinical-treatment-guideline-for-tobacco-cessation-in-adults) (World Health Organization, 2024); [DailyMed - VARENICLINE tablet, film coated VARENICLINE kit](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=78d1857f-8708-5410-792f-4a3e5e7971a5) (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 13 (McGraw Hill, 2023); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=N07BA) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/classes/smoking-cessation-medicines/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/classes/smoking-cessation-medicines/