Mysimba – Naltrexone Hydrochloride / Bupropion Hydrochloride Uses, Dose And Side Effects


Mysimba prolonged release tablets are Naltrexone Hydrochloride/Bupropion Hydrochloride

What Is Mysimba Is And What Is Mysimba Used For

Mysimba contains 2 active substances: naltrexone hydrochloride and bupropion hydrochloride and is used in adults with overweight or obese to lose weight along with a calorie-reduced diet and physical activity. The drug acts on areas of the brain that are involved in controlling food intake and energy consumption.

Obesity in adults over 18 years is defined as a BMI (body mass index) greater than or equal to 30 and obesity in adults over 18 years is defined as a BMI greater than or equal to 27 and less than 30. BMI is calculated as measured body weight (kg) divided by measured length elevated in the square (m 2 ).

Mysimba is approved for use in patients with a BMI at the onset of 30 or greater. It can also be given to people with a BMI between 27 and 30 if the people also have other diseases that are linked to weight, such as. treated high blood pressure ( hypertension ), type 2 diabetes, or high blood fats (blood lipids).

Your doctor may discontinue treatment with Mysimba after 16 weeks if you have not lost at least 5 percent of your starting weight. Your doctor may also recommend that you stop treatment if there is any uncertainty about high blood pressure or other uncertainties about safety and how well you tolerate this medicine.

What You Need To Know Before Using Mysimba

Do Not Use Mysimba

  • If you are allergic to naltrexone, bupropion or any of the other Mysimba ingredients (listed in section 6)
  • If you have abnormally high blood pressure ( hypertension ) that is not being treated with a medicine
  • If you have a condition that causes seizures or if you have had seizures before
  • If you have a brain tumor
  • If you usually drink large amounts of alcohol and have just stopped or will stop while taking Mysimba
  • If you have recently stopped taking sedatives or anxiolytics (especially benzodiazepines ) or if you will stop taking them while taking Mysimba
  • If you have or have had bipolar disorder (intense mood swings)
  • If you are taking other medicines containing bupropion or naltrexone
  • If you have or have had an eating disorder (eg bulimia or anorexia )
  • If you are currently addicted to long-term treatment with opiates or opioid agonists (eg methadone ) or if you are undergoing acute withdrawal (“rapid withdrawal”)
  • If you are taking monoamine oxidase inhibitors ( MAOIs ) which are medicines for depression or Parkinson’s disease or have been taking them for the last 14 days
  • If you have severe liver disease 
  • If you have terminal kidney failure.

Warnings And Cautions

Talk to your doctor or pharmacist before taking Mysimba.

This is important because some conditions make you more likely to get side effects (see also section 4).

If you feel depressed, have suicidal thoughts, have previously had suicidal thoughts, or have any other mental health problems, ask your doctor before taking this medicine.


Mysimba can cause seizures in up to 1 in 1,000 patients (see also section 4). Talk to your doctor before taking this medicine:

  • If you have had a serious head or head injury
  • If you regularly drink alcohol (see section “Mysimba with alcohol”)
  • If you regularly use medicines that help you sleep (sedatives)
  • If you are currently addicted to or abusing cocaine or other stimulants
  • If you have diabetes and use insulin or diabetes medicine in tablet form, it may cause low blood sugar ( hypoglycaemia )
  • If you are taking medicines that may increase the risk of seizures (see section “Other medicines and Mysimba”).

If you have a seizure, stop taking Mysimba and contact your doctor immediately.

You should stop taking Mysimba immediately and contact a doctor if you get any symptoms of an allergic reaction such as 

  • Swelling of the throat, tongue, lips, or face
  • Difficulty swallowing
  • Difficulty breathing
  • Dizziness
  • Fever
  • Rash
  • Joint pain
  • Muscle aches
  • Itching
  • Hives after taking this medicine (see also section 4).

You must tell your doctor about

  • You have high blood pressure before taking Mysimba as it may worsen. Your blood pressure and heart rate are measured before you start taking Mysimba and while you are taking it. If your blood pressure or heart rate increases significantly, you may need to stop taking Mysimba
  • You have coronary heart disease (a disease caused by poor blood flow in the blood vessels of the heart) that is not kept under control with symptoms such as. angina (characterized by chest pain) or have recently had a heart attack
  • You have or have had a condition that affects the blood circulation in the brain ( cerebrovascular disease )
  • You have any liver problems before you start taking Mysimba
  • You have some kidney problems before you start taking Mysimba
  • You have previously had mania (feeling of being elated or hurried which causes an unusual behavior).
  • you are taking antidepressants as the use of these medicines with Mysimba may lead to serotonin syndrome, a potentially life-threatening condition (see “Other medicines and Mysimba” in this section and section 4) .


If you are 65 years of age or older, use Mysimba with caution. Mysimba is not recommended if you are over 75 years old.

Children And Young People

No studies have been performed on children and adolescents under 18 years of age. Mysimba should therefore not be given to children and adolescents under 18 years of age.

Other Medicines And Mysimba

Tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines.

Do not take Mysimba  with:

  • Monoamine oxidase inhibitors (medicines used to treat depression or Parkinson’s disease ) such as phenelzine, selegiline or rasagiline You must stop taking these medicines for at least 14 days before you start taking Mysimba (see section “Do not take Mysimba”).
  • Opiates and drugs containing opiates , e.g. 
    • For the treatment of cough and cold such as 
      • Mixtures containing dextromethorphan or codeine
    • Opiate dependence eg 
      • Methadone 
    • Pain eg
      • Morphine
      • Codeine
    • Diarrhea eg
      • Paregoric

You should stop all opiates at least 7-10 days before you start taking Mysimba. Your doctor may take a blood test to check that your body has got rid of these medicines before starting treatment. Naltrexone blocks the effects of opiates. If you take higher Mysimba dosage of your opiates to counteract this effect of naltrexone, you may experience an acuteopiate poisoning, which can be life-threatening. When your treatment with Mysimba is stopped, you may be more sensitive to low doses of opiates (see section “Do not take Mysimba”).

Tell your doctor if you are taking any of the following medicines, as your doctor will monitor you closely for side effects:

  • Drugs that can, when used alone or in combination with naltrexone / bupropion, increase the risk of seizures , eg:
    • Medicines for depression and other mental disorders
    • Cortisone (except for drops, creams or lotions for eye or skin problems, or inhaler for respiratory diseases such as asthma )
    • Drugs used to prevent malaria
    • Quinolones ( antibiotics such as ciprofloxacin to treat infections )
    • Tramadol (a painkiller belonging to the class opiates)
    • Theophylline (used to treat asthma )
    • Antihistamines (medicines to treat hay fever, itching and other allergic reactions) that can cause drowsiness (eg chlorphenamine), medicines to lower blood sugar (eg insulin , sulphonylureas such as glyburide or glibenclamide and meglitinides such as nateglinide or repaglinide)
    • Medicines that help you sleep (sedatives such as diazepam )
  • Antidepressants eg
    • Amitriptyline
    • Desipramine
    • Imipramine
    • Venlafaxine
    • Paroxetine
    • Fluoxetine
    • Citalopram and escitalopram)
  • Other mental disorders eg 
    • Risperidone
    • Haloperidol
    • Thioridazine
  • Mysimba may interact with certain medicines used to treat depression and you may experience so-called serotonin syndrome. Symptoms are mental changes eg
    • Arousal
    • Hallucinations
    • Coma  and other effects such as 
      • Body temperature above 38 ° C
      • Increased heart rate, unstable blood pressureand excessive reflexes
      • Muscle stiffness
      • Lack of coordination and / or gastrointestinal symptoms eg
        • Nausea
        • Vomiting
        • Diarrhea) (see section 4).
  • Certain medicines used to treat high blood pressure ( beta blockers such as metoprolol and clonidine – a centrally acting antihypertensive agent)
  • Certain medicines for irregular heartbeat (eg propafenone and flecainide )
  • Certain anticancer medicines (eg cyclophosphamide, ifosfamide and tamoxifen)
  • Certain medicines for Parkinson’s disease (eg levodopa , amantadine and orphenadrine)
  • Ticlopidine or clopidogrel which is mainly used to treat heart disease or stroke
  • Drugs for the treatment of HIV infection or AIDS , e.g. efavirez and ritonavir
  • Drugs for the treatment of epilepsy , e.g. valproate , carbamazepine, phenytoin and phenobarbital.

Your doctor will monitor you closely for side effects and may need to adjust the Mysimba dosage of one of the other medicines or Mysimba.

Mysimba may make other medicines less effective if taken at the same time:

  • If you take digoxin for heart

If this applies to you, tell your doctor. Your doctor may consider adjusting your digoxin dose.

Mysimba With Food, Drink And Alcohol

Mysimba with alcohol

High alcohol consumption during treatment with Mysimba may increase the risk of seizures, mental disorders and may result in reduced alcohol tolerance. Your doctor may advise you not to drink alcohol while taking Mysimba or to try to drink as little as possible. If you are currently drinking heavily, do not stop suddenly, as you may have a seizure.

Pregnancy, Breastfeeding And Fertility

Mysimba should not be used during pregnancy or breastfeeding.

If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Driving And Using Machines

  • Consult your doctor before driving and using machines as Mysimba may make you feel dizzy and sleepy, which may affect your ability to concentrate and react.
  • Do not drive, use tools or machines, and do not perform dangerous activities until you know how this medicine affects you.
  • If you experience fainting, muscle weakness, or cramps during treatment, do not drive or use machines.
  • In case of doubt, consult your doctor, who may consider discontinuing treatment depending on your situation.

Mysimba Contains Excipients

Mysimba contains lactose (a sugar)

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.

How To Use Mysimba

  • Always take this medicine exactly as your doctor has told you. Ask your doctor or pharmacist if you are unsure.
  • The initial dose is usually one tablet (8 mg naltrexone hydrochloride / 90 mg bupropion hydrochloride) once a morning. Dose one is gradually increased as follows:
    • Week 1 : One tablet daily in the morning
    • Week 2 : Two tablets daily, one in the morning and one in the evening
    • Week 3 : Three tablets daily, two in the morning and one in the evening
    • Week 4  and onwards : Four tablets daily, two in the morning and two in the evening
  • The recommended maximum dose of Mysimba tablets per day is two tablets taken twice a day. After 16 weeks and every year after starting treatment, your doctor will decide if you should continue to take Mysimba.
  • If you have liver or kidney problems, or if you are older than 65, and depending on the severity of the problem, your doctor may carefully evaluate whether this medicine is suitable for you or recommend that you take another dose and monitor you more closely for potential side effect ar. If you have high blood sugar ( diabetes ) or if you are over 65 years old, your doctor may take a blood sample before starting treatment with Mysimba to determine if this medicine is suitable for you or if you need to take another dose.
  • This medicine should be swallowed. The tablets should be swallowed whole. The tablets must not be divided, chewed, or crushed and should preferably be taken with food.

If You Use More Mysimba Than You Should 

If you have taken too many tablets, the risk of having a seizure or other side effects similar to those described in section 4 below increases. Do not wait, contact a doctor or the nearest emergency department immediately.

If You Forget To Use Mysimba

Skip the missed dose one and take the next dose at the usual time. Do not take a double dose to make up for a forgotten dose.

If You Stop Using Mysimba

You may need to take Mysimba tablets for at least 16 weeks for it to achieve full effect. Do not stop taking Mysimba without talking to your doctor first.

If you have any further questions on the use of this product, ask your doctor or pharmacist.

Possible Mysimba Side Effects

Like all medicines, Mysimba tablets can cause side effects, although not everybody gets them.

Serious side effects are

Tell your doctor immediately if you notice any of the following serious side effects:

  • Suicidal thoughts and feeling depressed

The frequency of Mysimba side effects

  • Suicide attempts
  • Suicidal behavior
  • Suicidal ideation
  • Feeling depressed is not known and can not be estimated from the data available in people taking Mysimba.

There have been reports of depression, suicidal ideation, and suicide attempts during treatment with Mysimba. If you have thoughts of harming yourself or other anxious thoughts, or if you are depressed and notice that you are feeling worse or developing new symptoms, contact your doctor immediately or see a hospital.

  • Seizures:

Rare – may affect up to 1 in 1,000 people taking Mysimba at risk of seizures.

Symptoms of seizures include convulsions and usually loss of consciousness. A person who has had a seizure may be confused afterward and may not remember what happened. The risk of seizures is higher if you take too much, if you take certain other medicines or if you run a higher risk than usual for seizures (see section 2).

  • Erythema multiforme and Stevens-Johnson syndrome

No known frequency – can not be calculated from the data available in people taking Mysimba.

Erythema multiforme is a severe skin condition that can affect the mouth and other parts of the body, with red, often itchy spots that start on the arms and legs. Stevens-Johnson syndrome is a rare skin disease with severe blisters and bleeding in the lips, eyes, mouth, nose, and genitals.

  • Rhabdomyolysis

No known frequency – can not be calculated from the data available in people taking Mysimba. 

Rhabdomyolysis is an abnormal breakdown of muscle tissue that can lead to kidney problems. Symptoms include severe muscle cramps, muscle pain, or muscle weakness. 

  • Lupus rash or worsening lupus symptoms

No known frequency – can not be calculated from the data available in people taking Mysimba. Lupus is a disease of the immune system that affects the skin and other organs. If you experience lupus eruption, rash, or lesions (especially in areas exposed to sunlight) while taking Mysimba, you should contact a doctor immediately, as it may be necessary to discontinue treatment.

  • Serotonin syndrome that can be exhibited gives expression as mental changes (eg arousal, hallucinations or coma ) and other effects such as body temperature above 38 ° C, increased heart rate, unstable blood pressure and excessive reflexes, muscle stiffness, lack of coordination and / or gastrointestinal symptoms (eg nausea, vomiting or diarrhea) when Mysimba is taken with medicines used to treat depression (t. eg paroxetine , citalopram , escitalopram, fluoxetine and venlafaxine (see section 2) No known frequency – (can not be calculated from the data available in people taking Mysimba).

Other side effects include:

Very common side effects (may affect more than 1 user in 10):

  • Nausea or vomiting
  • Constipation
  • Headache

Common side effects (may affect up to 1 in 10 people):

  • Anxiety
  • Dizziness, feeling dizzy or dizzy ( vertigo )
  • Tremors
  • Difficulty sleeping (make sure you do not take Mysimba near bedtime)
  • Taste changes (dysgusi)
  • Dry mouth
  • Concentration difficulties
  • Feeling tired (fatigue) and drowsiness, drowsiness or lack of energy ( lethargy )
  • Tinnitus
  • Fast or irregular heartbeat
  • Hot flashes
  • Increased blood pressure (sometimes severe)
  • Pain in the upper abdomen
  • Abdominal pain
  • Increased sweating ( hyperhidrosis )
  • Skin rash and itching ( pruritus )
  • Hair loss ( alopecia )
  • Irritability
  • Feeling nervous

Uncommon side effects (may affect up to 1 in 100 people):

  • Hives ( urticaria )
  • Hypersensitivity
  • Abnormal dreams
  • Nervousness
  • Intoxication
  • Tension
  • Anxiety
  • Mood swings
  • Tremors in the head or an arm or a leg, which are aggravated when trying to perform a certain movement (intention tremor)
  • Balance disorders
  • Memory loss ( amnesia )
  • Tingling or numbness in the hands or feet
  • Motion sickness
  • Belching
  • Discomfort in the abdomen
  • Indigestion
  • Inflammation of the gallbladder (cholecystitis)
  • Elevated creatinine in the blood (indicates renal impairment)
  • Elevated liver enzymes and elevated bilirubin
  • Lliver disease
  • Difficulty getting and maintaining an erection
  • Feel abnormal
  • Weakness ( asthenia )
  • Thirsty
  • Feel warm
  • Chest pain
  • Increased appetite
  • Weight gain

Rare side effects (may affect up to 1 in 1,000 people): 

  • Low number of certain white blood cells (decreased number of lymphocytes )
  • Decreased number of hematocrit (indicating decreased volume of red blood cells )
  • Swollen / swollen / swollen eyelids, face, lips, tongue or throat, which can cause great difficulty in breathing ( angioedema )
  • Excessive loss of body fluid (dehydration)
  • Hallucinations
  • Fainting
  • Unconsciousness
  • Almost fainting (presyncope)
  • Seizures
  • Fresh blood comes out through the rectum usually in or with feces (hematochezi)
  • An organ or tissue comprising an organ is pushed out through the wall or cavity in which it is usually located ( hernia )
  • Toothache
  • Caries 
  • Cavities in the teeth
  • Pain in the lower abdomen
  • Liver damage due to drug poisoning
  • Pain in the jaw
  • A disease characterized by a sudden compelling need to urinate (urination)
  • Irregular menstrual cycles
  • Vaginal bleeding
  • Dryness of the vulva and vagina
  • Cold extremity you (hands, feet)

No known frequency of adverse reactions (can not be calculated from the available data):

  • Swollen glands in the neck, armpit or groin ( lymphadenopathy )
  • Mood disorders
  • Irrational ideas (delusions)
  • Psychosis
  • Lost sex drive
  • Feel hostile
  • Serious suspicion ( paranoia )
  • Aggressiveness
  • Attention deficit disorder
  • Nightmares
  • Confusion
  • Disorientation
  • Impaired memory
  • Restlessness
  • Muscle stiffness
  • Uncontrolled movements
  • Difficulty walking or coordination
  • Blurred vision
  • Eye pain
  • Eye irritation
  • Eye swelling
  • Watery eyes
  • Increased sensitivity to light ( photophobia )
  • Pain in the ears
  • Discomfort in the ears
  • Breathing difficulties
  • Nasal discomfort, nasal congestion, runny nose, sneezing, sinus problems
  • Sore throat, voice disorders, cough
  • Yawning
  • Hemorrhoids , ulcers
  • Diarrhea
  • Weather stresses ( flatulence )
  • Hepatitis
  • Acne
  • Pain in the groin
  • Muscle pain
  • Joint pain
  • Abnormal need to urinate
  • Painful to urinate
  • Overindulge
  • Increased energy

How To Store Mysimba

  • Keep this medicine out of the sight and reach of children.
  • Do not use this medicine after the expiry date which is stated on the carton after EXP and on the blister after EXP. The expiration date is the last day of the specified month.
  • Do not store above 30 ° C.

Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.

Contents Of The Pack And Other Information

Content Declaration

  • The active substances are naltrexone hydrochloride and bupropion hydrochloride. Each tablet contains 8 milligrams of naltrexone hydrochloride, equivalent to 7.2 milligrams of naltrexone and 90 milligrams of bupropion hydrochloride, equivalent to 78 mg of bupropion.
  • Other Mysimba ingredients(excipients) are:
    • Tablet core:  
      • Microcrystalline cellulose
      • Hydroxypropyl cellulose
      • Anhydrous lactose
      • Lactose monohydrate (see section 2 “Mysimba contains lactose”)
      • Cysteine ​​hydrochloride
      • Crospovidone type A
      • Magnesium stearate
      • Hypromellose
      • Disodium edetate
      • Colloidal silica
      • Indigo 13 carmine aluminum lacquer
  •  Film coating:
    • Poly (vinyl alcohol)
    • Titanium dioxide (E171)
    • Macrogol 3350
    • Talc
    • Indigo carmine aluminum lacquer (E132)

What The Medicine Looks Like And Contents Of The Pack

Mysimba prolonged-release tablets are blue, biconvex, round tablets debossed with “NB-890” on one side. Mysimba is available in packs of 28, 112 tablets. Not all pack sizes may be marketed.

Marketing Authorization Holder And Manufacturer

Orexigen Therapeutics Ireland Limited

2nd Floor

Palmerston House

Fenian Street

Dublin 2



MIAS Pharma Ltd

Suite 2 Stafford House, Strand Road, Portmarnock, Co. Dublin,


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