bupropion hydrochloride + naltrexone hydrochloride: clinical use

Prescribing considerations

• Confirm that the patient meets the licensed adult weight-management indication and that treatment accompanies dietary and physical-activity measures.
• Review opioid exposure, seizure risk, mental-health history, eating disorders, alcohol or sedative use, cardiovascular disease, renal and hepatic function, and the complete medication list.
• Use caution in older adults, controlled hypertension, coronary or cerebrovascular disease, diabetes treated with glucose-lowering medicines, and a personal or family history suggestive of Brugada syndrome.
• Plan for interruption or an alternative strategy where opioid analgesia may be needed.

Contraindications and cautions

• Uncontrolled hypertension
• Current or previous seizure disorder, or a known central nervous system tumour
• Acute alcohol or benzodiazepine withdrawal
• Current or previous bulimia or anorexia nervosa
• History of bipolar disorder
• Chronic opioid or opioid-agonist treatment, opioid dependence or acute opioid withdrawal
• Concurrent monoamine oxidase inhibitor treatment
• Concurrent products containing bupropion or naltrexone
• Severe hepatic impairment or end-stage renal failure
• Hypersensitivity to an active ingredient or excipient

Monitoring

• Measure blood pressure and pulse before treatment and periodically thereafter.
• Monitor tolerability, mood, suicidal thinking, behavioural change and symptoms of mania or psychosis.
• Reassess seizure risk and interacting medicines whenever treatment changes.
• Consider renal, hepatic and glucose-related factors where clinically indicated; review glucose-lowering treatment if weight loss increases hypoglycaemia risk.
• Stop and investigate suspected drug-induced liver injury, serious skin reaction, seizure or clinically important sustained blood-pressure or pulse elevation.

Clinical pharmacology

Bupropion weakly inhibits neuronal dopamine and noradrenaline reuptake and is metabolised mainly through CYP2B6; bupropion and hydroxybupropion inhibit CYP2D6. Naltrexone antagonises mu-opioid receptors and limits inhibitory opioid feedback on hypothalamic appetite pathways. Both active substances have clinically active metabolites, and renal elimination contributes to their clearance.

Formulation and product differences

• The product is a fixed-combination prolonged-release tablet rather than separate immediate-release components.
• The tablet is blue, round and marked “NB-890”; it must not be divided, chewed or crushed.
• It contains lactose and is subject to additional safety monitoring.

Modified-release tablet

Route: Oral

Strengths: 8 mg + 90 mg