Naltrexone hydrochloride and bupropion hydrochloride oral
- Drugs List
- Therapeutic Indications
- Precautions and Warnings
- Pregnancy and Lactation
- Side Effects
Oral formulation of naltrexone hydrochloride and bupropion hydrochloride.
Weight management in adults with BMI > 30 - adjunct
Weight management in adults with BMI 27 to < 30 with comorbidity -adjunct
One tablet to be taken every morning.
One tablet to be taken every morning and every evening.
Two tablets to be taken every morning and one tablet to be taken every evening.
Week 4 to week 16
Two tablets to be taken every morning and two tablets to be taken every evening.
After week 16, the patient should be re-assessed. If treatment is to continue the recommended dose of two tablets every morning and two tablets every evening should be administered and the patient should be re-assessed annually.
Maximum daily dose should not exceed 32mg naltrexone hydrochloride and 360mg bupropion hydrochloride.
Patients with Renal Impairment
Moderate or severe renal impairment:
Reduce maximum dose to 2 tablets daily (1 tablet in the morning, 1 tablet in the evening).
Children under 18 years
Patients over 75 years
Within 2 weeks of discontinuing MAOIs
Alcohol withdrawal syndrome
Central nervous system neoplasm
End stage renal disease
History of anorexia nervosa
History of opioid abuse
History of seizures
Severe hepatic impairment
Precautions and Warnings
Females of childbearing potential
High alcohol intake
Patients over 65 years
Predisposition to seizures
Congestive cardiac failure
Glucose-galactose malabsorption syndrome
History of mania
Mild hepatic impairment
Moderate renal impairment
Recent myocardial infarction
Patients at risk of suicide should be closely supervised
Reduce dose in patients with renal impairment
Advise ability to drive/operate machinery may be affected by side effects
Advise patient not to drive until they know how the medicine affects them
Monitor blood pressure pre-treatment and periodically thereafter
Screen for opioid use before treatment
Diabetic control may need adjustment
Discontinue treatment if patient develops seizures
Evaluate treatment efficacy regularly
Monitor heart rate pre-treatment and periodically thereafter
Monitor patients for signs and symptoms of Serotonin Syndrome
Monitor renal function in patients with risk factors for renal impairment
Potential for drug abuse
Reassess need for continued treatment at regular intervals
Advise patient to report symptoms of serum sickness
Advise patients/carers to seek medical advice if suicidal intent develops
Consider dose reduction or discontinuation if serotonin syndrome suspected
May activate mania or hypomania
May increase risk of seizure
Discontinue if allergic reaction occurs
Discontinue if AST or ALT level > 3x ULN and bilirubin > 2x ULN
Discontinue if heart rate is increased for sustained period
Discontinue if significant rise in blood pressure occurs
Stop therapy at 16 weeks if weight loss is less than 5% of initial weight
Suspend if drug induced liver injury is suspected
Advise patient against the use of opioids during treatment
Advise patient not to take St John's wort concurrently
Advise patient to avoid alcohol during treatment
Prior to initiating treatment, patients at high risk of renal impairment should have their glomerular filtration rate (eGFR) assessed.
Do not restart treatment if patient has had a seizure during treatment.
Temporarily discontinue treatment if patient requires opiate treatment.
Discontinue treatment if serum sickness is suspected.
Discontinue treatment if drug-induced liver injury is diagnosed.
The use of naltrexone hydrochloride and bupropion hydrochloride is not recommended for women attempting to conceive.
Pregnancy and Lactation
Naltrexone hydrochloride and bupropion hydrochloride is contraindicated during pregnancy.
The manufacturer does not recommend using naltrexone hydrochloride and bupropion hydrochloride during pregnancy.
At the time of writing there is limited published information regarding the use of naltrexone and bupropion in combination during pregnancy. Animal studies using naltrexone during pregnancy have shown teratogenic effects. The molecular weight of naltrexone suggests it does cross the placenta (Briggs et al, 2015) and Schaefer (2015) states that naltrexone is a potent opioid antagonist with a long half life.
Animal studies have not shown any increased risks of foetal malformations when using bupropion during pregnancy. However some studies have shown cardiovascular defects when bupropion was administered during the first trimester of pregnancy and a strong association of developing attention deficit hyperactivity disorder (ADHD) when used during the second trimester of pregnancy (Schaefer et al, 2015). Briggs (2015) states bupropion should be used during pregnancy if the potential benefits to the mother are necessary.
Naltrexone hydrochloride and bupropion hydrochloride is contraindicated during breastfeeding.
The manufacturer does not recommend breastfeeding whilst taking naltrexone hydrochloride and bupropion hydrochloride.
At the time of writing there is limited published information regarding the use of naltrexone and bupropion in combination during breastfeeding. Naltrexone and bupropion are excreted into breast milk. Briggs (2015) states one case where naltrexone was administered during breastfeeding showed no adverse effects on the infant, however the use of naltrexone during breastfeeding should be evaluated for each individual case. Schaefer (2015) and Hale (2014) also support that no adverse effects have been found when using naltrexone during breastfeeding.
Studies have shown milk production in breastfeeding women to be suppressed when using bupropion during breastfeeding (Hale et al, 2014). Briggs (2015) states mothers should be advised of the potential risks to the infant if using bupropion during breastfeeding.
Blood glucose disturbances
Blood pressure changes
Changes in libido
Decrease in haematocrit
Delayed hypersensitivity reactions
Disturbances of appetite
Elevation of liver enzymes
Increase in dental caries
Lability of affect
Loss of balance
Loss of consciousness (transient)
Serum creatinine increased
Serum sickness-like reactions
Thrombotic thrombocytopenic purpura
It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.
The following number will direct the caller to the relevant local centre (0844) 892 0111
Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).
Last Full Review Date: October 2019
Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.
Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.
Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.
Summary of Product Characteristics: Mysimba 8mg/90mg prolong-release tablets. Orexigen Therapeutics Ireland Limited. Revised June 2021.
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