Mysimba 8/

Mysimba combines naltrexone (an opioid antagonist) with bupropion (a noradrenaline and dopamine reuptake inhibitor) for chronic weight management in adults with a BMI of 30 or above, or 27 with comorbidities. The two drugs act on the hypothalamus and mesolimbic reward system to reduce appetite, cravings, and the rewarding aspects of eating. This addresses both the homeostatic and hedonic drivers of overeating.

How to Take Mysimba

Mysimba is started at one tablet in the morning and the dose is gradually increased over four weeks to reach the maintenance dose of two tablets in the morning and two tablets in the evening. This gradual increase helps reduce side effects, particularly nausea. Swallow tablets whole; do not crush or chew them.

Take Mysimba with food to reduce stomach upset. Do not take it with a high-fat meal, as this significantly increases the amount of the medication absorbed and raises the risk of side effects including seizures. Avoid skipping doses, but if you miss a dose, simply skip it and take the next one at the usual time, do not double up.

Week 1: 1 tablet in the morning. Week 2: 1 morning, 1 evening. Week 3: 2 morning, 1 evening. Week 4 onwards: 2 morning, 2 evening. Each tablet: 8 mg naltrexone / 90 mg bupropion.

Common Side Effects

Common side effects include:

• Nausea (most common, especially in the first few weeks, usually settles with time)
• Constipation
• Headache
• Insomnia
• Dry mouth
• Dizziness

Nausea is the most frequently reported side effect and is usually at its worst during the dose-escalation period. Eating smaller, more frequent meals can help. Mysimba contains bupropion, which lowers the seizure threshold, do not use if you have a history of seizures or eating disorders. Seek emergency medical attention if you experience a seizure.

Bupropion lowers the seizure threshold; contraindicated in seizure disorders. Monitor blood pressure, as bupropion can raise it. Naltrexone blocks opioid receptors; do not use opioid analgesics while taking Mysimba.

Contraindicated in seizure disorders, bulimia or anorexia nervosa, opioid dependence or current opioid use, concurrent MAO inhibitor use, uncontrolled hypertension, and severe hepatic impairment.