Bupropion belongs to the family of medications known as antidepressants. It is used for the treatment of depression (Wellbutrin® SR) and as an aid for quitting smoking (Zyban®). It works by affecting the balance of chemicals that occur naturally in the brain.

For the treatment of depression, the full effects of the medication may not be seen until after several weeks of treatment.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of bupropion for treatment of depression is 100 mg to 300 mg per day. Daily doses over 150 mg are divided into two doses. Do not exceed the maximum dose of 300 mg per day, and do not take a single dose greater than 150 mg. People with reduced liver or kidney function may require a lower dose.

Multiple daily doses should be taken at least eight hours apart. It is very important that bupropion tablets be swallowed whole.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is very important that this medication be taken on a regular schedule as prescribed by the doctor. If you miss a dose of this medication take it as soon as you remember it. If it is within eight hours of your next dose, skip the missed dose and carry on with your regular schedule. Do not take a double dose to make up for a missed one.

Wellbutrin® SR is available as 100 mg and 150 mg tablets.

100 mg: Each blue, round, film-coated, sustained-release tablet, printed "WELLBUTRIN SR 100", contains bupropion HCl 100 mg. Nonmedicinal ingredients: carnauba wax, cysteine hydrochloride, edible black ink, FD&C Blue No. 1 Lake, hydroxypropyl cellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, and titanium dioxide.

150 mg: Each purple, round, film-coated, sustained-release tablet, printed "WELLBUTRIN SR 150", contains bupropion HCl 150 mg. Nonmedicinal ingredients: carnauba wax, cysteine hydrochloride, edible black ink, FD&C Blue No. 2 Lake, FD&C Red No. 40 Lake, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, and titanium dioxide.

This medication should not be taken by anyone who:

• is taking another medication that contains bupropion (e.g., Zyban® or Wellbutrin® SR)
• has a seizure disorder
• has or has had an eating disorder (bulimia or anorexia nervosa)
• has taken a monoamine oxidase inhibitor (MAO inhibitor; e.g., phenelzine, tranylcypromine) within the past two weeks
• is currently taking thioridazine (an antipsychotic drug)
• is having abrupt withdrawal from alcohol or sedatives
• is allergic to bupropion or to any of the ingredients of this medication

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects may go away as your body becomes used to the medicine; check with your doctor if they continue or become bothersome.

More common
• abdominal pain
• constipation
• decrease in appetite
• dizziness
• dryness of mouth
• increased sweating
• nausea or vomiting
• trembling or shaking
• trouble sleeping
• weight loss (unusual)

Less common
• blurred vision
• change in sense of taste
• drowsiness
• feeling of fast or irregular heartbeat
• frequent need to urinate
• muscle pain
• sore throat
• unusual feeling of well-being

Check with your doctor as soon as possible if any of the following side effects occur:

More common
• agitation
• anxiety

Less common
• buzzing or ringing in ears
• headache (severe)
• skin rash, hives, or itching

Rare
• confusion
• extreme distrust
• fainting
• false beliefs that cannot be changed by facts
• hallucinations
• seizures (convulsions), especially with higher doses
• trouble concentrating

Symptoms of overdose
• fast heartbeat
• hallucinations
• loss of consciousness
• nausea
• seizures
• vomiting

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Identical medications: Wellbutrin® SR and Zyban® contain the same active ingredient (bupropion). Anyone taking one of these medications should not take the other or any other product containing bupropion, as the risk of seizures increases with an increased dosage.

Heart disease: There is no experience establishing the safety of bupropion for use by people with a recent history of heart attack or unstable heart disease.

Liver disease: Because bupropion is cleared from the body through both the liver and the kidney, caution and lower doses should be used by people with liver disease or kidney disease. Bupropion is not recommended for use by people with severe liver disease unless the benefits outweigh the risks.

Suicidal or agitated behaviour: Adults and children taking this medication may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. These symptoms may occur within several weeks after people start taking this medication. People should be closely monitored by their doctor for emotional and behavioural changes.

Stopping the medication: Stopping this medication suddenly may lead to side effects. If you are thinking of stopping the medication, check with your doctor first.

Drowsiness/reduced alertness: People taking bupropion should avoid operating hazardous machinery, including cars, until they are certain that the medication does not impair their mental alertness, judgment, or physical coordination.

Seizure risk: Bupropion should be used with extreme caution by people who are at increased risk of seizures. Things which increase the risk of seizures include:

• abrupt withdrawal from alcohol, benzodiazepines, or other sedatives
• addiction to cocaine, stimulants, or opiates (such as morphine)
• diabetes treated with oral medications or insulin
• excessive alcohol use
• history of head trauma or seizures (including epilepsy)
• tumours of the the brain or spinal cord
• use of other medications that make seizures more likely (e.g., antipsychotics, antidepressants, lithium, theophylline, steroids)
• use of over-the-counter stimulants or appetite suppressants

Pregnancy: The safety of bupropion during pregnancy has not been established. It has been reported that babies born to pregnant women who have taken medications of this kind during the last trimester of pregnancy may be adversely affected. Physicians and pregnant women should carefully consider the benefits and the risks of all treatment options.

Breast-feeding: Bupropion passes into breast milk. Because this medication presents risks to nursing infants, a decision should be made whether to discontinue breast-feeding or to discontinue bupropion, taking into account the importance of the medication to the mother.

Children: The safety and effectiveness of bupropion for use by children and adolescents under 18 years old have not been established. The use of this medication in children below the age of 18 may cause behavioural and emotional changes, such as suicidal thoughts and behaviour.

The following medications may affect how bupropion works or increase the risk of side effects:

• carbamazepine
• corticosteroids (e.g., prednisone)
• cyclophosphamide
• guanfacine
• levodopa
• lithium
• monoamine oxidase inhibitors (MAO inhibitors; e.g., phenelzine, tranylcypromine, moclobemide) - bupropion should not be started until at least 14 days after MAO inhibitors are stopped
• orphenadrine
• phenytoin
• phenobarbital
• ritonavir
• theophylline

The following medications may be affected by bupropion:

• antipsychotics (e.g., haloperidol, risperidone, thioridazine)
• beta-blockers (e.g., metoprolol)
• flecainide
• levodopa
• propafenone
• SSRIs (e.g., paroxetine, sertraline, fluoxetine)
• tricyclic antidepressants (e.g., nortriptyline, imipramine, desipramine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications.