Smoking Nicotine and Heart Health
Medical Disclaimer: This content is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Information is based on current medical literature and clinical guidelines but may not apply to your specific situation. Individual responses vary based on personal medical history and concurrent conditions. Always consult qualified healthcare providers for medical decisions. Never delay seeking medical care based on content you’ve read. If experiencing a medical emergency, seek immediate medical attention.
These articles provide education to enhance your healthcare partnership. All treatment decisions should involve your healthcare team. Use this knowledge to have informed discussions, not replace medical care.
In Brief
Because nicotine dependence is a physical condition, it responds to specific medical treatments. Three approaches have strong evidence: nicotine replacement therapy, which supplies nicotine without the smoke; the partial agonists varenicline and cytisine, which occupy the brain’s nicotine receptors to reduce both withdrawal and the reward of smoking; and bupropion, which acts through other brain chemistry.¹ Varenicline is the most effective single medication, more than doubling quit rates compared with placebo, with combination nicotine replacement — a patch plus a faster-acting form — close behind; bupropion and single-form nicotine replacement help meaningfully but somewhat less.²,³,⁴ Each improves a person’s chance of quitting when paired with behavioral support, and the most effective roughly double it. For a cardiovascular audience the central question is safety, and the evidence is reassuring: nicotine replacement is far safer than continued smoking and does not increase serious cardiovascular events, including in people with established heart disease, because the harm of smoking comes from combustion products rather than from nicotine itself.⁶,⁷,⁸ The nuances still matter — nicotine has real physiological effects, some situations call for caution, and the right choice depends on the individual — so these decisions belong with a healthcare team. This article explains how each medication works, how they compare, and what the safety evidence shows.
Medications Change the Odds
Most smokers know that medications to help with quitting exist, yet most serious quit attempts are still made without them. That gap matters, because nicotine dependence is a biological condition, and like many biological conditions, it responds better to treatment than to determination alone. Understanding how these medications work — and why they are considerably safer than many people believe — is one of the most useful parts of a successful quit attempt.
Despite strong guideline recommendations, cessation medications remain substantially underused. The reasons are recognizable: lingering safety concerns, misconceptions about nicotine, limited time for counseling in a clinical visit, and the persistent belief that quitting should be a matter of willpower. Current major guidelines, including those of the US Preventive Services Task Force, recommend behavioral support together with FDA-approved medication for most adults trying to quit, absent a contraindication.⁹
The rationale follows from the biology. Dependence is a physical process — receptors adapted to nicotine, a withdrawal syndrome when it is removed, and cravings triggered by both — so treatments that act on that same biology help, and the evidence shows they do. Paired with behavioral support, cessation medications substantially improve a person’s chance of quitting for good, with the most effective roughly doubling it.¹ Doubling the chance of success is a large treatment effect, but quitting remains hard: nicotine dependence is a chronic, relapsing condition, and medications improve the odds rather than guarantee the outcome.⁸
This is the fifth article in the series. The previous articles covered the harm, the dependence, and the recovery; this one covers the medications, and the next covers the behavioral strategies that work alongside them. The two are partners rather than alternatives — medication and support together outperform either alone — which is why this article and Article 6 are meant to be read together.
How the Medications Work
There are three evidence-based pharmacological approaches to quitting, and they map onto the biology described in Article 3.
The first is to replace the nicotine without the smoke. Nicotine replacement therapy delivers controlled doses of nicotine — through the skin or the lining of the mouth or nose — to reduce withdrawal and craving while the person breaks the behavioral habit, then tapers off.³ It supplies the addictive compound while eliminating the combustion products that cause cardiovascular and lung disease.
The second is to partially occupy the receptor. Varenicline and cytisine are nicotine receptor partial agonists: they bind the α4β2 receptor central to dependence and do two things at once.² As partial agonists, they stimulate the receptor enough to release some dopamine and ease withdrawal; as partial blockers, they occupy the receptor so that nicotine from a cigarette has less effect, reducing the reward of smoking.² A cigarette smoked while taking varenicline tends to be less satisfying.
The third is to act on other brain chemistry. Bupropion was developed as an antidepressant and aids cessation through separate mechanisms — increasing the availability of dopamine and norepinephrine and blocking nicotinic receptors — independent of the nicotine pathway itself.⁴ It is the option that contains no nicotine and is not a partial agonist.
These approaches address different components of the same dependence. Nicotine replacement reduces withdrawal by supplying nicotine without the smoke. Varenicline reduces both withdrawal and the reward of smoking by occupying the nicotine receptor — the dual action that makes it the most effective single agent. Bupropion works through separate neurotransmitter pathways that ease craving and withdrawal. The mechanisms differ, but each shifts the biological balance toward successful cessation. They also differ in how effective they are, what side effects they carry, and which person each suits best.
Nicotine Replacement Therapy
Nicotine replacement therapy (NRT) is the oldest and most widely available option, sold over the counter in many countries. It comes in two functional types. The long-acting form is the transdermal patch, which delivers a steady level of nicotine through the skin across the day. The faster-acting forms — gum, lozenge, inhaler, mouth spray, and nasal spray — deliver a smaller, quicker dose that can be used to handle a craving as it arrives.
Across trials, any form of NRT increases the chance of successfully quitting by roughly 50 to 60% compared with control — a relative risk of about 1.55.³ The faster-delivery forms such as sprays and lozenges tend to perform at least as well as gum, and the patch sits in the same general range.³ These are meaningful effects for a widely accessible, low-risk treatment.
The single most useful practical point about NRT is to use two forms together. A patch for steady background coverage, plus a faster-acting form for breakthrough cravings, is more effective than either alone, and combination NRT approaches varenicline — the most effective single agent — in effectiveness.³ Many people still picture the choice as patch or gum; the evidence points to patch and gum. Single-form use, on its own, is often underdosed.
Adherence is where many attempts quietly fail. A large share of apparent medication “failures” reflect inadequate dose, stopping too soon, or inconsistent use rather than a medication that did not work — the patch abandoned after a few days, the gum used once or twice, the dose kept too low.³ Used at an adequate dose for the recommended duration, these treatments perform as the trials describe.
Two points are frequently misunderstood. First, NRT is not equivalent to substituting one harmful habit for another: it delivers nicotine more slowly and at lower peak levels than a cigarette, without the reinforcing rapid hit, and it is designed to be tapered.⁷,⁸ It is also meant to replace cigarettes, not to supplement them — using it alongside continued smoking defeats the purpose. Second, the nicotine in NRT is not the source of smoking’s cardiovascular harm — the distinction developed in the safety section below, and the reason NRT is considered safe in situations where continued smoking is dangerous.
Varenicline
Varenicline is the most effective single medication for quitting smoking, and its dual mechanism is the reason: by both easing withdrawal and dampening the reward of smoking, it addresses two parts of dependence at once. In the pooled trial evidence, it more than doubled the chance of quitting compared with placebo — a relative risk of 2.32, with high-certainty evidence.² In absolute terms, the network meta-analysis estimates roughly 8 additional people quitting for every 100 treated with varenicline.¹ In head-to-head comparisons, varenicline outperformed both single-form NRT and bupropion.²,⁵
Many people find that cigarettes become less satisfying even before their quit date, a direct result of that dual action. The most common side effect is nausea, which is usually mild and often manageable by taking the medication with food; vivid or unusual dreams and insomnia are also common.⁵
Varenicline has carried a complicated safety reputation, and an accurate account matters. It was formerly sold with a boxed warning about serious neuropsychiatric effects, including mood changes and suicidal thoughts. That warning was tested directly in EAGLES, a large randomized trial conducted at the request of the FDA, comparing varenicline, bupropion, nicotine patch, and placebo in smokers both with and without psychiatric conditions.⁵ The trial found no significant increase in serious neuropsychiatric events with varenicline or bupropion relative to placebo or patch, and on that basis the FDA removed the boxed warning in 2016.⁵ The current evidence does show that people taking varenicline report slightly more serious adverse events overall than those not taking it — a relative risk of about 1.23 — so it is not free of risk; but the specific neuropsychiatric and cardiac concerns that drove the old warning were not borne out.² Anyone with a history of significant psychiatric illness should still quit under clinical guidance, but fear of these effects is no longer a sound reason to avoid an effective medication.
Cytisine
Cytisine is the same class of drug as varenicline — a nicotine receptor partial agonist — but it is a plant-derived compound that has been used for decades in parts of Central and Eastern Europe, and it is structurally similar to nicotine.² It works by the same dual mechanism: easing withdrawal while reducing the reward of smoking.
The evidence shows cytisine helps more people quit than placebo, with a relative risk of about 1.30 and moderate-certainty evidence.² Direct trials comparing cytisine with varenicline have not shown a clear difference in effectiveness, and additional trials are ongoing.² Its main practical advantages are cost and access: cytisine is considerably less expensive than varenicline, which makes it an increasingly important option worldwide, particularly where the newer medications are unaffordable or unavailable. Its side effects are generally mild and gastrointestinal. The main limitation is that it has been studied less extensively than varenicline or NRT, so some questions — including detailed cardiovascular safety data — remain less fully answered.²
Bupropion
Bupropion is a non-nicotine tablet, originally an antidepressant, that roughly matches single-form NRT in effectiveness.¹ It increased quit rates compared with placebo with a relative risk of 1.60 and high-certainty evidence.⁴ It was less effective than varenicline and less effective than combination NRT in direct comparisons.⁴
Its distinct profile makes it useful in specific situations. Because it is not a nicotine product and works through mood-related brain chemistry, it can be a reasonable choice for someone who also has depressive symptoms, or who particularly wants to avoid nicotine. It also tends to reduce the weight gain that can accompany quitting, which matters to some people. The important cautions are that bupropion lowers the seizure threshold and is therefore not appropriate for people with a seizure disorder or certain other conditions, and it can interact with other medications — which is why the choice belongs with a prescriber who knows the person’s history.⁴ Bupropion can also be combined with nicotine replacement or, in some cases, with varenicline, though the added benefit of these combinations is less certain.⁴
Comparing the Options
No single medication is right for everyone, but the evidence supports a rough ordering of effectiveness, confirmed by a large network meta-analysis pooling more than 150,000 participants.¹ The most effective options are varenicline and cytisine among the partial agonists, along with combination NRT; single-form NRT and bupropion are effective but somewhat less so.¹ The table below summarizes the comparison. Every figure is a relative effect from the cited trial evidence, and effectiveness is only one of the factors that determine the right choice.
| Medication | Type | Effect on quitting | Availability | Notable considerations |
| Varenicline | Partial agonist | Most effective single agent; RR ~2.32 vs placebo; ~8 more quitters per 100¹,² | Prescription | Nausea, vivid dreams; old neuropsychiatric warning not borne out in EAGLES⁵ |
| Cytisine | Partial agonist | RR ~1.30 vs placebo; comparable to varenicline in direct trials² | Prescription; varies by country, not FDA-approved in the US | Low cost, widely accessible; less extensively studied² |
| Combination NRT | Nicotine replacement | Approaches varenicline; more effective than a single form³ | Over the counter | Requires using two forms together³ |
| Single NRT | Nicotine replacement | RR ~1.55 vs control³ | Over the counter | Often underdosed when used alone³ |
| Bupropion | Non-nicotine (other chemistry) | RR ~1.60 vs placebo; less than varenicline⁴ | Prescription | Avoid with seizure disorder; no nicotine; may limit weight gain⁴ |
Cost, insurance coverage, and local availability vary substantially and often shape the real choice as much as effectiveness does. The practical takeaway is not to memorize a ranking but to recognize that several genuinely effective options exist, that the two most effective approaches — varenicline and combination NRT — are both widely available, and that the best choice depends on the person: their medical history, previous quit attempts, other conditions, cost, and preference. This is the kind of decision that benefits from a conversation with a clinician.
Cardiovascular Safety: The Central Question for This Audience
For readers of a cardiovascular platform, one question sits above the others: are these medications — especially the ones containing nicotine — safe for the heart? The evidence gives a clear and reassuring answer, with appropriate nuance.
Start with the distinction established in Article 3. Nicotine is responsible primarily for sustaining dependence. The overwhelming cardiovascular harm of smoking comes from the thousands of combustion products generated by burning tobacco — the oxidant gases, carbon monoxide, and fine particulates detailed in Article 1 — not from nicotine itself.⁸ That distinction is what explains why replacing nicotine while eliminating the smoke produces such a large reduction in cardiovascular risk. Nicotine is not harmless: it acutely raises heart rate and blood pressure through the sympathetic nervous system, causes coronary vasoconstriction, and increases the heart’s oxygen demand.⁸,¹⁰ But replacing a smoker’s nicotine while removing the smoke shifts the overall balance substantially. Nicotine replacement also delivers nicotine more slowly and at lower peak levels than smoking does; plasma nicotine on a full-dose patch is generally lower than in a typical smoker.⁸
The direct evidence supports this. In a randomized trial specifically in patients with established cardiac disease — a high-risk population — the nicotine patch did not significantly increase cardiovascular events compared with placebo.⁷ More broadly, EAGLES and its cardiovascular extension, the largest trial of its kind, followed more than 8,000 smokers and found no significant increase in major adverse cardiovascular events — cardiovascular death, heart attack, or stroke — with varenicline, bupropion, or the nicotine patch compared with placebo.⁶ This was consistent with earlier trials and meta-analyses in smokers with known cardiovascular disease.⁶
Several nuances complete the picture. Nicotine replacement can cause minor cardiovascular effects such as palpitations, which are distinct from serious events.⁸ The one situation calling for genuine caution is the immediate aftermath of an acute event — the days around an unstable presentation or a very recent heart attack — where treatment decisions should be individualized with the cardiology team, since the trials establishing safety generally enrolled stable patients rather than those in the acute phase. And these medications were studied and funded in part by their manufacturers, a fact worth noting when weighing the evidence, though the cardiovascular safety findings are consistent across independent studies.⁶
The overriding consideration is one of comparison. The relevant alternative to using a cessation medication is not a risk-free state; it is continued smoking, which is unambiguously dangerous for the heart. For the large majority of people, including most with stable cardiovascular disease, these medications are safe and are the bridge to the single most protective step they can take. The specific case of quitting during and after a cardiac event is covered in Article 10, and any individual decision belongs with the care team.
Pregnancy and Other Special Situations
A few groups warrant individualized decisions rather than a blanket rule. Pregnancy is the clearest example. Continued smoking in pregnancy carries substantial risks to both mother and fetus, while the evidence on cessation medications in pregnancy is limited: major guidelines recommend behavioral support as the first-line approach and consider the evidence on pharmacotherapy insufficient to draw firm conclusions, which makes the decision one to weigh carefully with a clinician rather than a step to take unaided.⁹ People with a seizure disorder (for bupropion), a significant psychiatric history (for closer monitoring), or an unstable recent cardiac event (for the timing of nicotine replacement) similarly need the choice tailored to their situation. In each case, the point is to match the treatment to the person — not to withhold effective help.
Medication Works Best With Support
One theme runs through the evidence: medication and behavioral support are partners. Cessation medications improve success rates on their own, but they work best when combined with behavioral help — counseling, structured support, a quitline, or a planned strategy for managing cravings and triggers. The pharmacology reduces the physical pull of withdrawal; the behavioral work addresses the conditioned cues and the practical situations that undo quit attempts. Neither fully substitutes for the other. The behavioral side — how to prepare, how to get through a craving, and how to use support — is the subject of Article 6, which is designed to be used together with this one.
Common Beliefs vs What the Evidence Shows
Several beliefs about cessation medications keep people from using treatments that would help them.
| Common Belief | What the Evidence Shows |
| “Nicotine replacement is just swapping one addiction for another, and it’s as bad for my heart as smoking.” | NRT delivers nicotine slowly and at lower levels than cigarettes, without the combustion products that cause the harm; it does not significantly increase serious cardiovascular events, even in people with cardiac disease.⁶,⁷ |
| “I have heart disease, so I can’t use these medications.” | In trials including people with established cardiac disease, cessation medications did not significantly raise cardiovascular event rates; for most, the real cardiovascular danger is continued smoking, though timing after an acute event needs individual guidance.⁶,⁷ |
| “Varenicline is dangerous — it causes serious mood problems.” | The large EAGLES trial found no significant increase in serious neuropsychiatric events, and the FDA removed the boxed warning in 2016; it remains the most effective single medication.²,⁵ |
| “Medications are a crutch; real quitting takes willpower.” | Unaided attempts usually fail; medication paired with support substantially increases the chance of quitting — the most effective options roughly doubling it — by acting on the physical dependence that determination alone does not address.¹,⁸ |
What This Means
The practical implications are straightforward. Effective medications exist, yet most people who try to quit do not use them — an important and addressable gap.
Consider medication rather than relying on determination alone. Given how much medication improves the odds, a quit attempt without it starts at a disadvantage. The most effective approaches — varenicline or combination nicotine replacement — are both widely available, one by prescription and one over the counter.¹,²,³
Use nicotine replacement properly, not sparingly. The common failure is underdosing: a single form used lightly, or a patch abandoned early. The combination of a patch plus a faster-acting form, at adequate doses and for the recommended duration, is what the evidence supports.³
Do not let fear of the medication maintain the smoking. For the large majority of people, including most with stable heart disease, nicotine replacement and the other cessation medications are safe — and far safer than the smoking they replace.⁶,⁷ Heart disease, pregnancy, a seizure disorder, a psychiatric history, or other medications are reasons to involve a clinician in the choice, not reasons to forgo treatment.
Pair it with support, and expect to fine-tune. Medication plus behavioral support works better than either alone. And the medication that works best on one attempt is not necessarily the one that succeeds on another; if a treatment does not work or is not tolerated, another often will.
What This Means for You
- Consider a cessation medication for any serious quit attempt. It substantially improves the odds, and the two most effective options — varenicline and combination nicotine replacement — are widely available.¹,²
- If using nicotine replacement, use it fully. A patch for steady coverage plus a faster-acting form for cravings, at adequate doses, outperforms a single product used sparingly.³
- Do not let fear of the medication keep you smoking. For most people, including most with stable heart disease, these treatments are safe — and far safer than continued smoking.⁶,⁷
- Involve a clinician if a specific factor applies. Heart disease, pregnancy, a seizure disorder, a psychiatric history, or other medications shape the right choice — a reason to get guidance, not to avoid treatment.⁴,⁵,⁷,⁹
- Pair medication with support, and adjust as needed. Medication and behavioral help work better together, and if one medication does not suit, another often will.¹
A note on safety. Cessation medications carry specific cautions: bupropion is not suitable for people with a seizure disorder, varenicline warrants attention to mood in those with a psychiatric history, and nicotine replacement immediately after an acute cardiac event needs individualized advice. These are reasons to choose with a clinician, not to avoid treatment. The underlying cardiovascular warning signs remain: sudden chest pain, pressure, or tightness; pain radiating to the arm, jaw, or back; sudden shortness of breath; sudden weakness, numbness, difficulty speaking, or facial drooping; sudden vision loss; a sudden severe headache; or loss of consciousness are potential emergencies — call emergency services immediately.
How Strong Is the Evidence?
Not all of the conclusions in this article rest on equally certain evidence, and knowing the difference is part of using it well. The table below summarizes how confident the current evidence is in each main conclusion, using the certainty ratings from the systematic reviews behind them.
| Conclusion | Strength of evidence |
| Varenicline more than doubles quit rates versus placebo | High¹,² |
| Any nicotine replacement improves quit rates | High³ |
| Combination NRT is more effective than a single form | High¹,³ |
| Bupropion improves quit rates | High⁴ |
| Cytisine improves quit rates | Moderate² |
| Cessation medications do not substantially increase serious cardiovascular events | High⁶,⁷ |
| Long-term cardiovascular safety data specific to cytisine | Limited² |
Clinical Bottom Line
Nicotine dependence is a physical condition with effective physical treatments. Varenicline is the most effective single medication, more than doubling quit rates (relative risk about 2.32; roughly 8 more quitters per 100), with combination nicotine replacement — a patch plus a faster-acting form — close behind; cytisine is comparably effective and low-cost, and bupropion and single-form nicotine replacement help meaningfully but somewhat less.¹,²,³,⁴ All substantially improve a person’s chance of quitting when paired with behavioral support, the most effective roughly doubling it. For the heart, the evidence is reassuring: these medications, including nicotine replacement, do not significantly increase serious cardiovascular events even in people with established cardiac disease, because smoking’s harm comes from combustion rather than from nicotine — and the relevant comparison is always against continued smoking, which is far more dangerous.⁶,⁷,⁸ Nicotine still has real physiological effects and specific situations call for caution, so the right choice, and its timing, belong with a healthcare team. Used well, modern cessation medications are among the most effective and most underused interventions in preventive cardiovascular medicine.
What Comes Next
This article covered the medications; the next covers the practical skill of quitting. Article 6 turns to preparation and craving control — how to set a quit plan, anticipate and defuse the triggers that end most attempts, get through a craving in the moment, and use counseling and support. Medication changes the physical odds; the behavioral work is how a person actually moves through the quit, and the two are strongest together.
Key Terms
Bupropion: A non-nicotine tablet, originally an antidepressant, that aids cessation through dopamine and norepinephrine pathways and nicotinic blockade; contraindicated in people with a seizure disorder.
Combination NRT: Using a nicotine patch for steady coverage together with a faster-acting form (gum, lozenge, spray, or inhaler) for cravings; more effective than a single form alone.
Cytisine: A plant-derived nicotine receptor partial agonist, similar to varenicline, that is effective and low-cost but less extensively studied.
Major adverse cardiovascular event (MACE): A composite safety outcome of cardiovascular death, nonfatal heart attack, and nonfatal stroke, used to assess drug cardiovascular safety.
Nicotine receptor partial agonist: A drug (varenicline or cytisine) that partly stimulates the α4β2 nicotine receptor to ease withdrawal while blocking nicotine from fully activating it, reducing the reward of smoking.
Nicotine replacement therapy (NRT): Treatment that supplies controlled nicotine — via patch, gum, lozenge, inhaler, or spray — without the combustion products of smoking, to ease withdrawal during quitting.
Varenicline: The most effective single cessation medication; a nicotine receptor partial agonist that eases withdrawal and reduces the reward of smoking.
References
- Lindson N, Theodoulou A, Ordóñez-Mena JM, et al. Pharmacological and electronic cigarette interventions for smoking cessation in adults: component network meta-analyses. Cochrane Database Syst Rev.2023;9(9):CD015226. https://doi.org/10.1002/14651858.CD015226.pub2
- Livingstone-Banks J, Fanshawe TR, Thomas KH, et al. Nicotine receptor partial agonists for smoking cessation. Cochrane Database Syst Rev. 2023;6(6):CD006103. https://doi.org/10.1002/14651858.CD006103.pub9
- Hartmann-Boyce J, Chepkin SC, Ye W, Bullen C, Lancaster T. Nicotine replacement therapy versus control for smoking cessation. Cochrane Database Syst Rev. 2018;5(5):CD000146. https://doi.org/10.1002/14651858.CD000146.pub5
- Hajizadeh A, Howes S, Theodoulou A, et al. Antidepressants for smoking cessation. Cochrane Database Syst Rev.2023;5(5):CD000031. https://doi.org/10.1002/14651858.CD000031.pub6
- Anthenelli RM, Benowitz NL, West R, et al. Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch in smokers with and without psychiatric disorders (EAGLES): a double-blind, randomised, placebo-controlled clinical trial. Lancet. 2016;387(10037):2507–2520. https://doi.org/10.1016/S0140-6736(16)30272-0
- Benowitz NL, Pipe A, West R, et al. Cardiovascular safety of varenicline, bupropion, and nicotine patch in smokers: a randomized clinical trial. JAMA Intern Med. 2018;178(5):622–631. https://doi.org/10.1001/jamainternmed.2018.0397
- Joseph AM, Norman SM, Ferry LH, et al. The safety of transdermal nicotine as an aid to smoking cessation in patients with cardiac disease. N Engl J Med. 1996;335(24):1792–1798. https://doi.org/10.1056/NEJM199612123352402
- Benowitz NL. Nicotine addiction. N Engl J Med. 2010;362(24):2295–2303. https://doi.org/10.1056/NEJMra0809890
- US Preventive Services Task Force. Interventions for tobacco smoking cessation in adults, including pregnant persons: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(3):265–279. https://doi.org/10.1001/jama.2020.25019
- Benowitz NL, Gourlay SG. Cardiovascular toxicity of nicotine: implications for nicotine replacement therapy. J Am Coll Cardiol. 1997;29(7):1422–1431. https://doi.org/10.1016/S0735-1097(97)00079-X
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