[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Anti-obesity drugs](https://durgical.com/en/pharmacology/classes/anti-obesity-drugs/) › Naltrexone and bupropion # Naltrexone and bupropion ## Anti-obesity drugs? Anti-obesity drugs ## Pregnancy: avoid? Not used in pregnancy; the prescriber is told at once if pregnancy occurs during treatment. An extended-release combination of an opioid antagonist and an antidepressant that acts on hunger and reward circuits; used with diet and exercise in obesity. Updated Nov 1, 2026 ## Quick facts **Group** [Anti-obesity drugs](https://durgical.com/en/pharmacology/classes/anti-obesity-drugs/) **Target** Hypothalamic appetite and brain reward circuits (opioid receptors and dopamine/noradrenaline reuptake) **Used for** Chronic weight management **Key effects** Nausea · Constipation or diarrhoea · Headache **Monitor** Weight · Blood pressure and heart rate · Mood **ATC** A08AA62 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Clinical What the labels mean - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action Bupropion inhibits the reuptake of dopamine and noradrenaline; naltrexone blocks opioid receptors. Together they are thought to act on the hypothalamic hunger centre and the mesolimbic reward system, reducing appetite and food cravings. - Bupropion raises dopamine and noradrenaline signalling - Naltrexone blocks opioid receptors - Hunger centre and reward system are damped - Less appetite and fewer food cravings ## Indications - Chronic weight management with a reduced-calorie diet and exercise in obesity, or overweight with weight-related conditions [Obesity →](https://durgical.com/en/conditions/obesity/) ## Adverse effects ### Common - Nausea (very common at the start), vomiting - Constipation or diarrhoea - Headache, dizziness, insomnia - Dry mouth, altered taste - Tremor, sweating, flushing, ringing in the ears ### Serious (rare, important) - Suicidal thoughts and changes in mood or behaviour (boxed warning for bupropion) - Seizures - Raised blood pressure and heart rate - Angle-closure glaucoma - Serious allergic and skin reactions - Precipitated opioid withdrawal, or overdose if opioids are taken to overcome the block ## Contraindications - Seizure disorder, or anorexia nervosa or bulimia - Uncontrolled high blood pressure - Chronic opioid use, opioid agonist treatment or acute opioid withdrawal - Abrupt stopping of alcohol, benzodiazepines, sedatives or antiseizure drugs - Use of an MAO inhibitor in the past 14 days - Other bupropion-containing products ## Key interactions **Opioid analgesics and opioid-containing cough or antidiarrhoeal medicines** Blocked by naltrexone; may precipitate withdrawal; avoided. **MAO inhibitors (including linezolid and methylene blue)** Contraindicated; at least 14 days are left between them. **Other bupropion products** Duplicate bupropion raises seizure risk. **Alcohol** Worsens side effects. ## What is monitored - Weight, to judge whether treatment continues - Blood pressure and heart rate - Mood, suicidal thoughts and behaviour, especially early and after dose changes - Eye pain or vision changes ## Administration and safety - Oral extended-release tablets, swallowed whole, not split, chewed or crushed. - Started low and increased weekly over the first weeks; taken twice a day. - Not taken with a high-fat meal. - Look-alike risk: not given together with other bupropion products (antidepressant or smoking-cessation forms). ## Pregnancy and breastfeeding Not used in pregnancy; the prescriber is told at once if pregnancy occurs during treatment. ## Nursing care - Before: seizure history, eating disorders, blood pressure, opioid use, MAOI use. - During: blood pressure, pulse, mood and suicidal thinking. - Teach that opioid pain medicines will not work well and that trying to overcome the block can cause overdose. - Teach to report seizures, eye pain or rash immediately. ## Pharmacokinetics **Absorption** Oral extended-release tablet; it is not taken with a high-fat meal. ## Memory aid NB = 'No Binge': Naltrexone blocks the opioid 'reward' of eating, Bupropion pushes the hunger centre to stop. Watch the B-side: seizures, BP, blues (mood). ## Test yourself Think of the answer, then tap the question to see it. ## Why can't a patient on naltrexone-bupropion receive usual opioid analgesia? Naltrexone blocks opioid receptors, so opioids work poorly and may precipitate withdrawal. ## Which seizure-related conditions contraindicate naltrexone-bupropion? Seizure disorder, eating disorders (anorexia, bulimia) or abrupt alcohol or benzodiazepine withdrawal. ## Which boxed warning comes from the bupropion component? Suicidal thoughts and behaviour, especially in young people. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/naltrexone-and-bupropion/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## What the labels mean **Pregnancy: avoid** Not used in pregnancy; the prescriber is told at once if pregnancy occurs during treatment. ## Connections ## Related drugs 3 - [Naltrexone](https://durgical.com/en/pharmacology/naltrexone/) - [Bupropion](https://durgical.com/en/pharmacology/bupropion/) - [Phentermine and topiramate](https://durgical.com/en/pharmacology/phentermine-and-topiramate/) ## Related conditions 1 - [Obesity](https://durgical.com/en/conditions/obesity/) [← Back to the class: Anti-obesity drugs](https://durgical.com/en/pharmacology/classes/anti-obesity-drugs/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [Naltrexone and Bupropion: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a619020.html) (MedlinePlus (U.S. National Library of Medicine), 2019); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=A08AA62) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/naltrexone-and-bupropion/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/naltrexone-and-bupropion/