Bupropion / Naltrexone

What it is and how it works

Bupropion, a weak inhibitor of neuronal dopamine and noradrenaline reuptake, stimulates hypothalamic pro-opiomelanocortin (POMC) neurones, while naltrexone, an opioid antagonist, blocks the beta-endorphin-mediated auto-inhibitory feedback on these neurones. The combination reduces appetite and food intake and may modulate reward-driven eating.

Indications

Adjunct to a reduced-calorie diet and increased physical activity for weight management in adults with a BMI of 30 kg/m² or more, or 27 kg/m² or more with weight-related comorbidities (e.g. type 2 diabetes, dyslipidaemia, controlled hypertension).

Dosage and administration (summary)

Oral (8 mg naltrexone / 90 mg bupropion prolonged-release tablets): titrated over 4 weeks from 1 tablet daily to a maintenance dose of 2 tablets twice daily; do not crush or chew. Discontinue if at least 5% of initial body weight has not been lost after 16 weeks.

Contraindications

Uncontrolled hypertension; current or past seizure disorder; CNS tumour; abrupt withdrawal of alcohol, benzodiazepines or antiepileptics; bipolar disorder; current bulimia or anorexia nervosa; current opioid or opiate agonist use or acute opiate withdrawal; concomitant MAO inhibitors or other bupropion/naltrexone products; severe hepatic impairment; end-stage renal failure; pregnancy.

Warnings and precautions

Bupropion lowers the seizure threshold in a dose-related manner. Monitor for suicidal thoughts, depression and neuropsychiatric symptoms; measure blood pressure and pulse before and during treatment. Bupropion inhibits CYP2D6 and interacts with many drugs; patients may be insensitive to opioid analgesics during treatment.

Pregnancy

Contraindicated in pregnancy; weight loss offers no benefit in pregnancy.

Storage and supply

Store below 25 °C in the original package.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.