O que é Zyban?
Zyban (bupropion hydrochloride) is a medicamento sujeito a receita médica approved by the Agência Europeia de Medicamentos (EMA) as an aid to smoking cessation in adults. It is an antidepressant — specifically an aminoketone class antidepressant — that was initially developed and used under the name Wellbutrin for treating depression, before being approved in a modified formulation specifically for smoking cessation.
Crucially, Zyban contains no nicotine. It works through an entirely different mechanism from nicotine replacement therapy (NRT), acting on the brain’s reward and motivational pathways to reduce the drive to smoke.
Como funciona Zyban work?
Bupropion’s mechanism of action in smoking cessation is not fully elucidated, but is understood to involve:
- Inhibition of dopamine reuptake: Bupropion blocks the reuptake of dopamine in the nucleus accumbens and other reward-related brain regions, partially compensating for the dopaminergic reward that nicotine provides. This may reduce the reinforcing effects of smoking and diminish cravings.
- Inhibition of noradrenaline (norepinephrine) reuptake: Noradrenergic effects may help manage nicotine withdrawal symptoms including irritability, anxiety, and difficulty concentrating.
- Weak nicotinic receptor antagonism: Some evidence suggests bupropion may also have a limited direct effect on nicotinic receptors, though this is considered a secondary mechanism.
The overall effect is a reduction in the urge to smoke and attenuation of withdrawal symptoms — without delivering nicotine or acting primarily through nicotine receptors (unlike Champix/varenicline).
Para quem é Zyban for?
Zyban is indicated for adult smokers who are motivated to stop smoking. It may be particularly appropriate for:
- Smokers who prefer a non-nicotine pharmacological approach
- Those who have not responded adequately to NRT alone
- Smokers with co-existing depressive symptoms (though careful monitoring is required)
- Those who cannot tolerate varenicline (Champix) due to gastrointestinal efeito secundários
Zyban is contraindicated in pacientes with:
- A current or prior history of seizures (any seizure disorder)
- A current or prior history of eating disorders (anorexia nervosa, bulimia nervosa)
- Bipolar disorder
- Severe hepatic cirrhosis
- Monoamine oxidase inhibitor (MAOI) use within the previous 14 days
- Abrupt discontinuation of alcohol or benzodiazepines (increased seizure risk)
- A CNS tumour
Zyban requires careful consideration and close monitoring in pacientes with:
- A history of depression or other psychiatric conditions
- Cardiovascular disease
- Liver or kidney impairment
Dosagem
Zyban is started before the paciente stops smoking, to allow therapeutic blood levels to develop.
| Phase | Dose | Duration | Notes |
|---|---|---|---|
| Week 1 (pre-quit) | 150 mg once daily | 6 days | Patient continues smoking |
| From Day 7 onwards | 150 mg twice daily | 7–9 weeks | Minimum 8 hours between doses |
| Total tratamento duration | — | 7–9 weeks | Quit date set at start of week 2 |
Key rules:
- Never exceed 150 mg per dose
- Ensure at least 8 hours between doses (twice daily dosing)
- Do not crush, chew, or halve the comprimidos
- Set a quit date in the first two weeks of tratamento
Efeitos secundários
Very common efeito secundários (affecting more than 1 in 10 people)
- Insomnia: One of the most frequently reported efeito secundários; taking the second daily dose in the early afternoon (not at bedtime) can help
- Dry mouth
- Headache
- Nausea
Efeitos secundários comuns
- Dizziness
- Agitation or anxiety
- Tremor
- Constipation
- Skin reactions including rash or itching
- Elevated blood pressure
Serious risks
- Seizures: The most clinically significant safety concern. The risk is approximately 1 in 1,000 at the recommended doses; higher with dose escalation or in pacientes with predisposing factors. Zyban must be stopped immediately if a seizure occurs.
- Neuropsychiatric effects: Changes in mood, behaviour, or thinking — including depression, suicidal ideation, hostility, and agitation — have been reported. These may be related to nicotine withdrawal, the medicamento, or both.
- Hypersensitivity reactions: Including severe rash (Stevens-Johnson syndrome, rarely). Stop Zyban and seek medical attention for any serious skin reaction.
- Hypertension: Blood pressure monitoring is recommended, particularly in pacientes with existing cardiovascular conditions.
Zyban vs alternativas
| Treatment | Mechanism | Nicotine-free | Prescription Required | Relative Efficacy |
|---|---|---|---|---|
| Zyban (Bupropion) | Dopamine/noradrenaline reuptake inhibitor | Yes | Yes | Moderate |
| Champix (Varenicline) | Partial nicotinic agonist | Yes | Yes | Highest (pharmacological) |
| NRT | Nicotine replacement | No | Generally No | Moderate |
Champix (varenicline) generally shows higher quit rates in head-to-head studies with bupropion. However, Zyban may be preferred where varenicline is not tolerated or is contraindicated. The decision should be made with a prescribing médico.
Como aceder a Zyban online na Europa
Zyban is a medicamento sujeito a receita médica in all estados-membros da UE. It cannot be dispensed without a valid receita médica from a qualified medical professional.
Prescrivia operates as a technology intermediary, connecting pacientes with independent EU-registered médicos for online health assessments. We do not prescribe medicamentos, employ médicos, or sell medicamentos directly. If an independent médico determines that bupropion is clinically appropriate following a thorough assessment, they may issue a receita médica, which is fulfilled by a licensed EU farmácia partner.
Important: A Prescrivia não garante that a receita médica will be issued. All clinical decisions are made independently by qualified medical professionals, particularly given Zyban’s important contraindications.
Informação de segurança importante
Stop Zyban and procure assistência médica imediata if you experience:
- A seizure or convulsion
- Severe skin reaction (rash with blistering or peeling)
- Significant mood changes, suicidal thoughts, or unusual behaviour
Do not take Zyban if you:
- Have a history of seizures or eating disorders
- Are taking MAOIs or have taken them in the past 14 days
- Are drinking large amounts of alcohol or using benzodiazepines and plan to stop abruptly
Alcohol: Zyban may lower seizure threshold; excessive alcohol consumption further increases this risk. Alcohol should be minimised or avoided during tratamento.
Fontes
Medical information on this page is based on the following sources:
- Agência Europeia de Medicamentos (EMA). Zyban (bupropion) — Summary of Product Characteristics. ema.europa.eu
- Agência Europeia de Medicamentos (EMA). Assessment report: Zyban. EMEA/H/C/000144.
- Organização Mundial da Saúde (WHO). Tobacco — Fact sheet. who.int
This content is reviewed periodically to reflect updated clinical guidance. It is provided for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for advice relevant to your individual health circumstances.
Frequently asked questions
- O que é Zyban and how is it different from other stop-smoking medicamentos?
- Zyban (bupropion) is an antidepressant medicamento that has been repurposed and approved for smoking cessation. Unlike nicotine replacement therapy (NRT), it contains no nicotine. Unlike Champix (varenicline), it does not work on nicotinic receptors. Instead, it acts on dopamine and noradrenaline pathways in the brain to reduce cravings and nicotine withdrawal symptoms.
- Why is Zyban so much more expensive than NRT?
- Zyban is a medicamento sujeito a receita médica that requires a médico consultation, and its production involves a more complex pharmaceutical manufacturing process than NRT products. The price reflects these factors. However, its effectiveness makes it cost-effective compared to the long-term costs — financial and health-related — of continued smoking.
- Can I take Zyban if I have a history of depression?
- Zyban is an antidepressant medicamento (bupropion), but its use for smoking cessation requires careful consideration in people with a history of depression. Bupropion can affect mood, and the interaction between its antidepressant effects and nicotine withdrawal can be complex. A médico will assess whether Zyban is appropriate for you based on your full psychiatric history. Zyban must not be used in pacientes with a current eating disorder or a history of seizures.
- Does Zyban lower the seizure threshold?
- Yes. Bupropion reduces the seizure threshold — meaning it can make seizures more likely in people predisposed to them. This is a dose-dependent effect and is one of the most important safety considerations with Zyban. It is contraindicated in pacientes with a history of seizures, eating disorders (bulimia, anorexia nervosa), and certain other conditions. Never exceed the prescribed dose.
- When do I set my quit date when starting Zyban?
- Zyban is started 1–2 weeks before the intended quit date, while the paciente continues to smoke. This allows adequate blood levels of bupropion to build up before the quit date. Patients typically set their quit date for around the end of the first week or start of the second week of tratamento.
Tratamentos
A Prescrivia é apenas uma plataforma intermediária. Não prestamos serviços médicos, não prescrevemos tratamentos nem dispensamos medicamentos. Todas as decisões médicas são tomadas por médicos independentes registados na UE. Todos os medicamentos são dispensados por farmácias licenciadas na UE. Esta plataforma facilita a ligação entre pacientes e prestadores de cuidados de saúde.