Abstain SR is a 150 mg sustained‑release tablet formulation of bupropion hydrochloride indicated for major depressive disorder, seasonal affective disorder, and as an aid to smoking cessation; it delivers 150 mg of the aminoketone antidepressant in a twice‑daily regimen, exerting its effects via inhibition of norepinephrine and dopamine reuptake and non‑competitive antagonism at nicotinic receptors, with common adverse effects including insomnia, dry mouth, and dizziness, and a dose‑related risk of seizures in susceptible individuals .
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Composition & Formulation
Active Ingredient: Bupropion hydrochloride 150 mg, in a polymer‑matrix sustained‑release tablet .
Excipients: Typical SR excipients (e.g., hydroxypropyl methylcellulose) and film‑coating agents to provide 12‑hour release; exact proprietary blend varies by manufacturer .
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Mechanism of Action
Norepinephrine–Dopamine Reuptake Inhibition (NDRI): Blocks presynaptic reuptake of norepinephrine and dopamine, enhancing synaptic concentrations of these mood‑modulating neurotransmitters .
Nicotinic Acetylcholine Receptor Antagonism: Non‑competitive inhibition at α4β2 nicotinic receptors, reducing nicotine‑induced dopamine release and thus aiding smoking cessation .
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Pharmacokinetics
Absorption: Oral SR tablets yield peak bupropion plasma levels at approximately 3 hours post‑dose (Tₘₐₓ ≈ 3 h), with hydroxybupropion peaking around 6 h .
Distribution: Bupropion is ~84% protein‑bound; volume of distribution is large owing to lipophilicity .
Metabolism: Extensively hepatic via CYP2B6 to three active metabolites (hydroxybupropion, threohydrobupropion, erythrohydrobupropion) .
Elimination: Bupropion half‑life ~21 h; hydroxybupropion half‑life ~20 h; excreted primarily in urine (87%) and feces (10%) .
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Indications & Uses
Major Depressive Disorder (MDD): Monotherapy for acute depressive episodes .
Seasonal Affective Disorder (SAD): Prophylactic and treatment use during seasonal depressive phases .
Smoking Cessation Aid: Reduces cravings and withdrawal symptoms in nicotine‑dependent individuals .
Off‑Label Uses: ADHD, bipolar depression augmentation, and weight management in combination with naltrexone .
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Dosage & Administration
Standard Regimen: 150 mg SR tablet taken orally twice daily, with doses ≥ 8 hours apart, preferably in the morning and early afternoon .
Titration: May increase to 300 mg/day (150 mg BID) after 3 days if tolerated; maximum 400 mg/day in divided doses, under close supervision .
Duration: For smoking cessation, continue 7–12 weeks; longer treatment for depression or SAD guided by clinical response .
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Contraindications
Seizure Disorders: History of epilepsy or previous seizure .
Eating Disorders: Current or prior diagnosis of bulimia or anorexia nervosa due to increased seizure risk .
MAOI Use: Concomitant or within 14 days of discontinuing reversible or irreversible monoamine oxidase inhibitors .
Abrupt CNS Depressant Withdrawal: Recent cessation of alcohol, benzodiazepines, barbiturates, or antiepileptic drugs .
Hypersensitivity: Known allergy to bupropion or any tablet component .
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Side Effects & Precautions
Common Adverse Reactions: Insomnia, headache, dry mouth, nausea, constipation, dizziness, sweating, tremor .
Serious Risks: Seizures (dose‑related incidence ~0.4% at 300–450 mg/day), hypertension, neuropsychiatric symptoms including suicidality .
Pregnancy & Lactation: Use only if benefits outweigh risks; limited human data suggest possible congenital defects .
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Drug Interactions
CYP2B6 Substrates/Inhibitors: Potential interactions altering bupropion metabolism (e.g., clopidogrel, ticlopidine) .
CNS Depressants: Alcohol, sedatives, antiepileptics may exacerbate neuropsychiatric side effects .
Drugs Lowering Seizure Threshold: Avoid co‑administration with other pro‑convulsant agents (e.g., tramadol, theophylline) .
MAOIs: Risk of hypertensive crisis and serotonin syndrome .
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Storage, Packaging & Pricing
Packaging: 150 mg film‑coated SR tablets in blister packs of 20 or bottles of 30 .
Storage: Store at 20–25 °C; protect from moisture and light; keep out of reach of children .
Pricing (Egypt/Tunisia): Approximately 20 EGP or TND for a pack of 20 tablets .
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References
DailyMed: Bupropion HCl SR prescribing info
Drugs.com: Bupropion SR patient information
Rosheta.com: Abstain SR 150 mg tablet details
Med.tn: Abstain SR pricing & composition
Doctorak.com: Abstain SR usage & adverse effects
Wikipedia: Bupropion overview
PMC: Bupropion neuropharmacolo
gy review
NCBI Bookshelf: Bupropion pharmacokinetics
PubMed: SR vs IR pharmacokinetics
FDA AccessData: Zyban contraindications
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