How bupropion works
Bupropion affects the balance of nerve messengers (neurotransmitters) in the brain. Experts attribute its effect against depression, smoking cessation and obesity to this.
Neurotransmitters are the signal transducers between nerve cells:
Triggered by an electrical impulse, a nerve cell can release a neurotransmitter into the tiny gap (synapse) that is the point of contact with the next nerve cell. The messenger migrates to the neighboring cell, docks there and also triggers an electrical impulse there.
As a result, a signal is transmitted. Afterwards, the first nerve cell takes up the messenger again, which ends its effect.
Mode of action in depression
Experts believe that a lack of neurotransmitters such as dopamine and norepinephrine in the brain is partly responsible for depression. This is where bupropion comes in:
It inhibits the reuptake of norepinephrine and dopamine into the cell of origin, allowing the neurotransmitters to exert their effects for longer. This alleviates depressive symptoms and has a stimulating effect.
Mode of action in smoking cessation
Dopamine plays an important role in the body’s “reward system”. The neurotransmitter is released primarily during pleasant sensations (e.g., smoking).
By prolonging the effects of dopamine, bupropion can support smoking cessation.
Together with the drug naltrexone, doctors use bupropion to treat severe obesity. The combination of active ingredients has an appetite-suppressing effect. However, the exact mechanism of action is still unclear.
Absorption, breakdown and excretion
Bupropion is taken as a tablet and passes through the intestinal wall into the blood. In the blood, bupropion binds to plasma proteins and is distributed throughout the body in this way.
The active substance is broken down in the liver and excreted in the urine. After about 20 hours, the original amount of active substance in the body has halved again (half-life). The metabolites of bupropion have a half-life of 20 to 36 hours.
When is bupropion used?
Bupropion is it approved for the treatment of:
- depression (EU, Switzerland)
- @ withdrawal symptoms during smoking cessation (Germany)
The fixed combination of bupropion and naltrexone is approved in the EU for the treatment of:
- Obesity: Body mass index (BMI) 30 or more.
- Obesity, with a BMI of 27 or more to less than 30, when associated with complications such as diabetes, abnormally elevated blood lipids, or hypertension
Taking the fixed combination is intended as an adjunct to other weight-reducing measures (dietary changes and increased physical activity).
How bupropion is used
Bupropion for depression: Adults take 150 milligrams of bupropion once daily. If needed, increase the dose to 300 milligrams twice daily with a doctor’s approval.
Bupropion takes effect after about seven to 28 days. How long patients take the drug depends on the course of their depression.
Bupropion for smoking cessation: Adults take 150 milligrams of bupropion once a day for the first six days. Those who tolerate the drug well can then increase the dose to 300 milligrams daily after consulting a doctor.
Bupropion for obesity: To help lose weight, take the fixed combination of bupropion and naltrexone according to the following schedule:
- 1st week: one tablet per day
- 2nd week: one tablet in the morning and one in the evening every day
- 3rd week: two tablets in the morning and one tablet in the evening
- From the 4th week: two tablets each in the morning and evening
If you have not lost at least five percent of your initial weight after 16 weeks of use, you should stop treatment with the bupropion-naltrexone preparation.
What are the side effects of bupropion?
Very common side effects of bupropion include insomnia, headache, dry mouth, and gastrointestinal upset (such as nausea and vomiting).
Bupropion may also cause hypersensitivity reactions (such as hives), loss of appetite, increased blood pressure, and tremors.
You can read more about possible side effects in the package leaflet of your bupropion medicine. If you suspect such unwanted side effects of taking the medicine, please contact your doctor or pharmacist.
People with depression sometimes develop suicidal thoughts. Such thoughts may increase initially as soon as you start taking antidepressants. This is because it takes time for the medication to take full effect.
Driving and operating machinery
Bupropion may cause dizziness, impaired concentration and coordination, among other things. Therefore, watch out for such side effects at the start of treatment before driving a vehicle or operating machinery.
When should you not take bupropion?
Adults should not use bupropion if:
- allergy to the active ingredient or other components of the medication
- tumors of the central nervous system
- severe cirrhosis of the liver
- concomitant use of monoamine oxidase inhibitors (MAO inhibitors – also used to treat depression)
- epilepsy
- eating disorders (like bulimia or anorexia)
Bupropion is not approved for children and adolescents under 18 years of age.
These drug interactions may occur with bupropion
Certain medicines speed up the breakdown of bupropion. This may decrease its effectiveness. These drugs include:
- HIV medications (such as ritonavir and efavirenz).
Conversely, bupropion inhibits the breakdown of some medications. Therefore, if you are using any of the following medications, you should seek prior advice from your doctor or pharmacy:
- Anti-arrhythmic drugs (such as propafenone, flecainide).
- Cardiac glycosides (such as digoxin)
- Beta-blockers (cardiovascular medication)
- Insulin (diabetes medication)
- Medicines for Parkinson’s disease (e.g., levodopa, amantadine)
- Agents for psychotic symptoms (antipsychotics such as risperidone, thioridazine)
- Antidepressants (e.g., tricyclic antidepressants and selective-serotonin reuptake inhibitors)
- Tamoxifen (breast cancer treatment)
- Tramadol (pain reliever)
Bupropion during pregnancy and breastfeeding.
There are better studied agents than bupropion for treating depression during pregnancy. However, if you are already stable on bupropion before this time, experts advise you to continue the therapy. Talk to your doctor about this.
Pregnant women should not take bupropion for smoking cessation. In general, women should try to quit smoking during pregnancy without medication.
The fixed combination of bupropion and naltrexone for weight loss is not suitable for pregnant women. Women who are planning to become pregnant should also not take the combination drug.
If the breastfeeding baby develops symptoms such as cramps, restlessness, vomiting, diarrhea, or immobilization (sedation) that cannot be explained in any other way (such as an infection), you should see your pediatrician.
How to get medicine with bupropion
Bupropion is only available in Germany, Austria, and Switzerland from pharmacies with a prescription. The same applies to the fixed combination of bupropion and naltrexone for weight reduction approved in the EU.
