Wellbutrin SR (bupropion hydrochloride sustained-release) is a widely prescribed antidepressant belonging to the aminoketone class, distinct from commonly used selective serotonin reuptake inhibitors (SSRIs). It is specifically formulated to provide a controlled, sustained release of bupropion, ensuring stable plasma concentrations over a 12-hour dosing interval. This mechanism supports consistent therapeutic effects in the management of major depressive disorder (MDD), while its unique neurochemical profile offers a favorable side effect spectrum for appropriate patient populations. Clinicians value its efficacy, particularly in cases where SSRI-induced sexual dysfunction or weight gain are concerning, making it a versatile option in psychopharmacology.

Features

• Active ingredient: Bupropion hydrochloride (sustained-release formulation)
• Available strengths: 100 mg, 150 mg, and 200 mg tablets
• Pharmacologic class: Aminoketone antidepressant; norepinephrine-dopamine reuptake inhibitor (NDRI)
• Dosing frequency: Twice daily (approximately 12 hours apart)
• FDA-approved for the treatment of major depressive disorder (MDD)
• Bioavailability: Approximately 87% under fasting conditions
• Half-life: Average of 21 hours for bupropion and its active metabolites
• Special storage: Room temperature (20–25°C), protected from light and moisture

Benefits

• Reduces symptoms of depression such as low mood, anhedonia, and fatigue through enhanced norepinephrine and dopamine activity.
• Lower incidence of sexual dysfunction and weight gain compared to SSRIs, supporting long-term treatment adherence.
• Sustained-release formulation minimizes peak-trough fluctuations, reducing the risk of side effects like insomnia or agitation.
• May improve concentration, energy, and motivation due to its dopaminergic effects.
• Non-habit forming when used as directed, with no known withdrawal syndrome upon discontinuation.
• May be used as augmentation therapy in partial responders to other antidepressants.

Common use

Wellbutrin SR is primarily indicated for the treatment of major depressive disorder (MDD) in adults. It is also used off-label for seasonal affective disorder (SAD), attention-deficit/hyperactivity disorder (ADHD) in adults, and as an aid to smoking cessation (though the XL formulation is more commonly approved for this purpose). Its unique mechanism of action makes it particularly suitable for patients who have experienced undesirable effects such as weight gain or sexual dysfunction with other antidepressant classes.

Dosage and direction

The recommended starting dose for Wellbutrin SR is 150 mg once daily, preferably in the morning. After at least 3 days, the dose may be increased to 150 mg twice daily, with at least 8 hours between doses. The maximum recommended dose is 400 mg per day, given as 200 mg twice daily. Tablets should be swallowed whole and not crushed, chewed, or divided, as this may alter the release profile and increase the risk of adverse effects, including seizure. Dosage adjustments should be made cautiously in patients with hepatic or renal impairment.

Precautions

Patients should be monitored for worsening depression, suicidality, or unusual changes in behavior, especially during the initial weeks of treatment or after dosage changes. Wellbutrin SR may lower the seizure threshold; caution is advised in patients with a history of seizure, head trauma, or eating disorders. Use with caution in patients with hepatic or renal impairment, and dose adjustment may be necessary. Blood pressure should be monitored, as hypertension has been reported. Avoid use in patients with angle-closure glaucoma. Alcohol consumption should be minimized or avoided due to increased seizure risk.

Contraindications

Wellbutrin SR is contraindicated in patients with a seizure disorder or history of seizures. It must not be used in individuals with a current or prior diagnosis of bulimia or anorexia nervosa due to increased seizure risk. Concomitant use with monoamine oxidase inhibitors (MAOIs) is contraindicated; at least 14 days should elapse between discontinuing an MAOI and initiating Wellbutrin SR. Hypersensitivity to bupropion or any component of the formulation is also a contraindication.

Possible side effects

Common side effects (≥1%) include dry mouth, nausea, insomnia, headache, dizziness, and sweating. Less frequently, tremor, rash, tinnitus, and increased blood pressure may occur. Serious but rare adverse events include seizures (dose-dependent), allergic reactions, hallucinations, and severe hypertension. Any new or worsening psychiatric symptoms should be reported immediately. Most side effects are mild to moderate and often diminish with continued therapy.

Drug interaction

Wellbutrin SR is metabolized primarily by CYP2B6; inhibitors (e.g., ticlopidine, clopidogrel) or inducers (e.g., ritonavir, carbamazepine) of this enzyme may affect bupropion levels. Concomitant use with other drugs that lower seizure threshold (e.g., antipsychotics, antidepressants, theophylline) should be avoided. Caution is advised when using with drugs metabolized by CYP2D6 (e.g., beta-blockers, SSRIs, antipsychotics), as bupropion may inhibit their metabolism. Avoid use with levodopa and amantadine.

Missed dose

If a dose is missed, it should be taken as soon as remembered, unless it is almost time for the next dose. In that case, skip the missed dose and resume the regular schedule. Do not double the dose to make up for a missed one, as this may increase the risk of adverse effects, including seizure.

Overdose

Overdose may lead to seizures, hallucinations, tachycardia, and loss of consciousness. Fatal outcomes have been reported, often involving multiple drug ingestion. Management includes supportive care, ECG monitoring, and control of seizures with benzodiazepines. Activated charcoal may be useful if administered early. There is no specific antidote; hemodialysis is not likely to be effective due to high volume of distribution.

Storage

Store at room temperature (20–25°C) in a tightly closed container, protected from light, moisture, and excessive heat. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is intended for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting or changing any medication regimen. Individual patient responses may vary.

Reviews

Clinical studies and patient reports generally reflect positive outcomes with Wellbutrin SR, particularly regarding its favorable side effect profile compared to SSRIs. Many users note improvements in energy, focus, and mood without significant weight gain or sexual dysfunction. However, experiences with side effects such as insomnia or anxiety vary. Always discuss personal treatment responses with a prescribing clinician.