Wellbutrin SR (Bupropion): Comprehensive Patient Information
Basic Product Information
| International Non-Proprietary Name (INN) | Bupropion |
|---|---|
| Australian Brand Names | Wellbutrin SR, Zyban |
| ATC Code | N06AX12 |
| Available Forms and Strengths | Tablets, sustained release (SR): 150 mg |
| Manufacturers | GlaxoSmithKline Australia Pty Ltd and approved generics |
| Prescription Status | Prescription Only Medicine (Schedule 4, S4) |
Mechanism of Action
Wellbutrin SR (bupropion) is an antidepressant and smoking-cessation aid. In simple terms, it works by balancing chemicals called neurotransmitters (noradrenaline and dopamine) in the brain, which are often affected in conditions like depression or during nicotine withdrawal. Unlike many similar medications, it does not act directly on the serotonin system.
For specialists: Bupropion is a selective norepinephrine-dopamine reuptake inhibitor (NDRI). This action increases synaptic concentrations of noradrenaline and dopamine. There is minimal activity at serotonergic receptors, and it has weak antagonism at nicotinic acetylcholine receptors, contributing to its efficacy as a smoking-cessation treatment.
Pharmacokinetics
- Absorption: Wellbutrin SR is well-absorbed orally, with peak plasma concentration reached in about 3 hours (range: 2–5 hours).
- Metabolism: Metabolised in the liver primarily via CYP2B6 to active metabolites (hydroxybupropion, threohydrobupropion, erythrohydrobupropion).
- Elimination: Predominantly excreted via urine (87%), minor via faeces (10%).
- Duration of Action: The half-life of the parent compound is approximately 21 hours; active metabolites have half-lives of 20–37 hours, allowing for sustained-release formulations to be dosed twice daily.
Use in Everyday Life and Best Practices (English Context)
Wellbutrin SR is commonly prescribed in Australia for the treatment of depression (major depressive disorder) and as an aid to stop smoking (marketed as Zyban for this purpose). It is not the first-choice antidepressant in every case, but may be chosen for patients who have not responded to or cannot tolerate other treatments, or where sexual side effects or weight gain from other medicines are problematic.
- Typical adult dose: 150 mg once daily in the morning for three days, increased to 150 mg twice daily if tolerated.
- Tablets should be swallowed whole with water, not chewed, crushed, or divided, to maintain sustained-release properties.
- Always take at the same time each day to ensure stable levels in your system.
Never exceed the recommended dose. High doses of bupropion increase the risk of seizures.
Dosing in the Morning vs Evening
- Morning: Preferred, as bupropion may cause insomnia if taken too late in the day. Taking the second dose before mid-afternoon is advised.
- Evening: Should be avoided due to risk of disturbed sleep.
Tip: To minimise the chance of forgetting, link your dose to another regular morning activity, such as breakfast or brushing your teeth.
Taking With Food or on an Empty Stomach
Wellbutrin SR can be taken with or without food. Food does not significantly affect absorption, although taking with food may help reduce the risk of stomach upset. For those following common Australian dietary habits—a mix of Western and Mediterranean-type diets—there are no specific food restrictions, but limit or avoid high-fat meals if you are concerned about gastrointestinal side effects.
Interaction Warnings
Some medicines, substances, or foods can interact with Wellbutrin SR. Always check with your doctor or pharmacist before starting new medicines or supplements.
| Interaction | Advice |
|---|---|
| Alcohol | Limit intake; alcohol increases risk of seizures and can worsen side effects. |
| CYP2B6 inhibitors/inducers (e.g., orphenadrine, clopidogrel) | May alter bupropion levels; dosage adjustments could be needed. |
| Other antidepressants (SSRIs, TCAs, MAOIs) | Risk of interactions or increased side effects; MAOIs must be stopped at least 14 days before starting bupropion. |
| Antipsychotics, anti-epileptics | May increase seizure risk or alter drug levels. |
| Nicotine replacement products (including patches/gum) | Increased risk of hypertension; monitor blood pressure. |
| St John’s Wort, herbal remedies | Possible increased risk of side effects; consult healthcare provider. |
Indications
| Indication | Notes (Australia context) |
|---|---|
| Major depressive disorder (MDD) | Approved and commonly prescribed; PBS-subsidised with restrictions |
| Smoking cessation (Zyban) | Approved, may be PBS-subsidised for eligible patients |
| Seasonal affective disorder (SAD) | Not approved in Australia; rarely used off-label |
| ADHD, weight management | Not officially approved; use is uncommon and off-label only |
Dosing According to Clinical Indications
| Population | Indication | Starting Dose | Usual Maintenance Dose | Maximum Dose |
|---|---|---|---|---|
| Adult (18–65) | MDD | 150 mg once daily | 150 mg twice daily | 300 mg/day |
| Adult | Smoking cessation | 150 mg once daily (3 days), then 150 mg twice daily | 150 mg twice daily (7–12 weeks) | 300 mg/day |
| Elderly (>65) | MDD, cessation | Start with caution at 150 mg once daily | Monitor closely; may not tolerate >150 mg/day | 150 mg/day (usually) |
| Pediatric (<18) | Any indication | Not routinely recommended or approved | --- | --- |
Safety Profile and Side Effects
Like all medicines, Wellbutrin SR may cause side effects, although not everyone gets them. Most are mild and temporary, but some may need medical attention.
| Side Effect | Frequency | Notes |
|---|---|---|
| Dry mouth, nausea, vomiting | Common | Usually mild; take with food if needed |
| Insomnia | Common | Avoid late doses |
| Headache, dizziness | Common | Monitor and report if persistent |
| Increased sweating | Common | Hydrate as needed |
| Anxiety or agitation | Occasional | May subside with continued use |
| Seizures | Rare (<1/1,000) | Higher risk with high doses, predisposing conditions |
| Hypersensitivity (rash, swelling) | Rare | Seek urgent medical help if suspected |
| Unusual mood changes, suicidal thoughts | Rare, serious | Contact doctor immediately |
Guidelines for Proper Use in Australia
- Always take Wellbutrin SR exactly as prescribed. Do not stop or change your dose without consulting your GP or psychiatrist.
- Store tablets below 25°C and out of reach of children.
- If you miss a dose, skip it and continue as normal. Do not double up.
- Do not drive or use machinery until you know how this medicine affects you.
- Arrange regular reviews with your doctor and discuss any side effects experienced.
- Prescription refills are required – repeats can be managed via your My Health Record or pharmacy e-scripts.
- Dispose of unwanted medication safely at your local pharmacy (Return Unwanted Medicines project).
Alternative Treatment Options
- SSRIs (e.g., sertraline, escitalopram): First-line, well-tolerated, fewer restrictions but may cause sexual dysfunction or weight gain.
- SNRIs (e.g., venlafaxine, duloxetine): Broad efficacy, potential for withdrawal symptoms, PBS-listed.
- Mirtazapine: Good for coexisting insomnia and anxiety, sedation and weight gain common.
- Noradrenergic and Specific Serotonergic Antidepressants (NaSSA): Alternative for some; available on PBS.
- Nicotine replacement therapy (for smoking cessation): Range of products available (patches, gum, inhalers), safer in cardiovascular disease, PBS-reimbursed.
- Varenicline (for smoking cessation): More effective than placebo, but limited use due to neuropsychiatric warnings.
Comparison: Wellbutrin SR is less likely to cause sexual side effects or weight gain than SSRIs/SNRIs. However, it is less effective for anxiety and should not be used with a history of seizures.
Legal, Registration, and Reimbursement Status in Australia
- Registered by the Therapeutic Goods Administration (TGA) as Wellbutrin SR and Zyban.
- Available only on prescription (Schedule 4, S4).
- Disease indication-dependent PBS reimbursement, mainly for major depressive disorder and nicotine dependence; consult your doctor or pharmacist for eligibility.
- Not a controlled drug, but dispensing is regulated and monitored through the Pharmaceutical Benefits Scheme (PBS) and My Health Record.
Latest Research and Clinical Guidance (2022–2025)
- Bupropion is an established second-line antidepressant in Australia, with current guidelines favouring its use for patients with sexual dysfunction or excessive weight gain from SSRIs or SNRIs (Australian Therapeutic Guidelines: Psychotropic, 2024 update).
- National recommendations from the Royal Australian and New Zealand College of Psychiatrists (RANZCP, 2023) underscore caution in patients with risk factors for seizures.
- The Lancet Psychiatry (2023) meta-analysis supports efficacy for smoking cessation, especially in combination with behavioural support, and highlights the importance of cardiovascular and psychiatric monitoring.
- No major new safety concerns identified as of 2025; rare but serious neuropsychiatric and seizure risks remain most significant in decision-making.
Availability and Delivery
| Pack Size | Form & Strength | Indicative PBS Price* | Availability |
|---|---|---|---|
| 30 tablets | SR 150 mg | AUD $6.30 (concession); ~$37.00 (general) | Most major Australian pharmacies |
| 60 tablets | SR 150 mg | Price varies | On order |
*PBS prices as of June 2024. Private prices may differ.
| City | Typical In-Store or Delivery Time |
|---|---|
| Sydney, Melbourne, Brisbane | 1 business day (in stock), 1–2 business days (delivery) |
| Perth, Adelaide, Hobart | 1–2 business days (delivery), 2–3 if regional |
| Darwin, Regional/Remote | Up to 3–5 business days (delivery), check for specific availability |
Frequently Asked Questions (FAQ)
1. Can I drink alcohol while taking Wellbutrin SR?
Alcohol should be limited or avoided, as it may increase the risk of seizures and worsen potential side effects. Discuss alcohol use with your doctor or pharmacist before starting.
2. What should I do if I miss a dose?
Skip the missed dose and take your next dose at the usual time. Do not take an extra tablet to make up for the missed dose, as this can increase the risk of side effects, especially seizures.
3. Will Wellbutrin SR affect my sleep?
Insomnia is a common side effect, particularly if taken late in the day. For best results, take your doses in the morning and early afternoon.
4. Is it safe to use in pregnancy or breastfeeding?
Bupropion is not generally recommended during pregnancy or breastfeeding unless absolutely necessary. Discuss risks and benefits with your healthcare provider.
5. How long does it take to work?
You may notice some improvement in mood or energy within 1–2 weeks, but full benefits may take 4–6 weeks. For smoking cessation, set a quit date ideally in the second week of treatment.
Always consult your GP, psychiatrist, or pharmacist for personalised advice. This information does not replace medical consultation.
