Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Wellbutrin SR (Bupropion). If you are concerned about side effects, discuss the risks and benefits of Wellbutrin SR (Bupropion) with your doctor.

The following side effects have been reported by at least 1% of people taking Wellbutrin SR (Bupropion). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• appetite changes
• bloating
• Constipation
• dizziness
• Dry Mouth
• headache
• nausea
• trembling or shaking
• trouble sleeping
• vomiting
• weight changes

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

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

• aggression
• agitation
• anxiety
• buzzing or ringing in ears
• confusion
• false beliefs that cannot be changed by facts
• hallucinations
• headache (severe)
• hostility
• inability to pass urine
• increased blood pressure
• low sodium levels in the blood (e.g., tiredness, weakness, confusion, with achy, stiff, or uncoordinated muscles)
• new or worsened emotional or behavioural problems
• signs of liver problems (e.g., nausea, vomiting, Diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
• worsening emotional problems

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with Fever or discomfort
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• symptoms of serotonin syndrome (e.g., confusion, fast heartbeat, hallucinations, restlessness, shaking, shivering, sudden jerking of muscles, sweating)
• thoughts of self-harm or suicide

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 Wellbutrin SR (Bupropion).

Do not use Wellbutrin SR (Bupropion) if you:

• are allergic to Wellbutrin SR (Bupropion) or to any of the ingredients of the medication
• are currently taking thioridazine (an antipsychotic medication) or have taken it in the past 2 weeks
• are having abrupt withdrawal issues from alcohol, benzodiazepines (e.g., Diazepam, Clonazepam, Lorazepam), or other sedatives (e.g., Phenobarbital)
• are taking another medication that contains Wellbutrin SR (Bupropion) (e.g., Zyban® or Wellbutrin® XL)
• have a seizure disorder or a history of seizures
• have or have had an eating disorder (bulimia or anorexia nervosa)
• have taken a monoamine oxidase inhibitor (MAO inhibitor; e.g., Phenelzine, Tranylcypromine) within the past 2 weeks

There may be an interaction between Wellbutrin SR (Bupropion) and any of the following:

• alcohol
• amphetamines (e.g., amphetamine, Dextroamphetamine, Lisdexamfetamine)
• antihistamines(e.g., doxylamine, Diphenhydramine, Hydroxyzine)
• anti-malarial medications (e.g., chloroquine, Mefloquine)
• anti-Parkinson medications (e.g., amantadine, Apomorphine, Bromocriptine, levodopa, Pramipexole, Ropinirole) – dopamine agonists
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Risperidone, thioridazine)
• Atomoxetine
• beta-blockers(e.g., Metoprolol, Propranolol, Timolol)
• caffeine
• Carbamazepine
• Clopidogrel
• Codeine
• Cyclophosphamide
• Dabrafenib
• dexmethylphenidate
• Dextromethorphan
• Digoxin
• Doxorubicin
• Duloxetine
• efavirenz
• Eliglustat
• Fesoterodine
• Flecainide
• Galantamine
• Gefitinib
• Hydrocodone
• Linezolid
• lithium
• lumacaftor and Ivacaftor
• Meperidine
• Methylphenidate
• Metoclopramide
• Mexiletine
• mifepristone
• Mirtazapine
• monoamine oxidase inhibitors (MAO inhibitors; e.g., phenelzine, tranylcypromine, Moclobemide, Selegiline) – Wellbutrin SR (Bupropion) should not be started until at least 14 days after MAO inhibitors are stopped
• nelfinavir
• Nicotine replacement therapy (e.g., nicotine patch)
• phenobarbital
• Phenytoin
• primidone
• promethazine
• Propafenone
• rifampin
• ritonavir
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• Tamoxifen
• Tamsulosin
• Tetrabenazine
• theophylline
• Ticlopidine
• Tolterodine
• Tramadol
• tricyclic antidepressants (e.g., Nortriptyline, Imipramine, Desipramine)
• Venlafaxine
• Vilazodone

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. 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 Wellbutrin SR (Bupropion). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications 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, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Wellbutrin SR (Bupropion).

Drowsiness/reduced alertness: Wellbutrin SR (Bupropion) may affect the mental or physical abilities needed to drive or operate machinery. Avoid driving, operating machinery, or performing other hazardous tasks until you have determined how Wellbutrin SR (Bupropion) affects you.

Glaucoma: Wellbutrin SR (Bupropion) may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how Wellbutrin SR (Bupropion) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Wellbutrin SR (Bupropion), and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking Wellbutrin SR (Bupropion).

Heart disease: It is not known whether Wellbutrin SR (Bupropion) is safe for use by people with a recent history of Heart Attack or unstable heart disease, as it can cause increased blood pressure.  If you have heart problems, discuss with your doctor how Wellbutrin SR (Bupropion) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Wellbutrin SR (Bupropion), and whether any special monitoring is needed.

Identical medications: Wellbutrin®, Zyban®, and several other medications contain the same active ingredient (Wellbutrin SR (Bupropion)). If you are taking one of these medications, do not take the other or any other product containing Wellbutrin SR (Bupropion), as the risk of seizures increases with an increased dosage. To reduce the risk of seizures, the total daily dose of Wellbutrin SR (Bupropion) should not be greater than 300 mg.

Kidney function: Wellbutrin SR (Bupropion) is removed from the body by the kidney. Decreased kidney function can cause Wellbutrin SR (Bupropion) to build up in the body, causing side effects. If you have Kidney Disease, discuss with your doctor how Wellbutrin SR (Bupropion) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Wellbutrin SR (Bupropion), and whether any special monitoring is needed.

Liver function: Wellbutrin SR (Bupropion) is removed from the body by the liver. Decreased liver function can cause Wellbutrin SR (Bupropion) to build up in the body, causing side effects. If you have liver disease, discuss with your doctor how Wellbutrin SR (Bupropion) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Wellbutrin SR (Bupropion), and whether any special monitoring is needed.

Wellbutrin SR (Bupropion) may also cause a decrease in liver function. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Seizure risk: Wellbutrin SR (Bupropion) may increase the risk of seizures. If you are at risk of seizures, discuss with your doctor how Wellbutrin SR (Bupropion) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Wellbutrin SR (Bupropion), and whether any special monitoring is needed.

Things which increase the risk of seizures include:

• addiction to cocaine, stimulants, or opiates (such as Morphine)
• Diabetes treated with oral medications or insulin
• excessive alcohol use
• history of head trauma
• history of seizures (including Epilepsy)
• severe liver problems
• tumours of 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

Serotonin syndrome: Severe reactions are possible when Wellbutrin SR (Bupropion) is combined with other medications that act on serotonin, such as tricyclic antidepressants and serotonin reuptake inhibitors ­– other medications used to treat depression. Similar effects occur when too much Wellbutrin SR (Bupropion) is taken or is allowed to build up in the body. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. These reactions should be treated as a medical emergency and immediate medical treatment should be obtained as coma and death are possible.

Stopping the medication: Stopping Wellbutrin SR (Bupropion) suddenly may lead to side effects. If you are thinking of stopping the medication, check with your doctor first.

Suicidal or agitated behaviour, or other behaviour changes: Adults and children taking Wellbutrin SR (Bupropion) 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 Wellbutrin SR (Bupropion). If you experience these side effects or notice them in a family member who is taking Wellbutrin SR (Bupropion), contact your doctor immediately. Your doctor will monitor you for emotional and behavioural changes while you are taking Wellbutrin SR (Bupropion).

Pregnancy: The safety of Wellbutrin SR (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. If you become pregnant while taking Wellbutrin SR (Bupropion), contact your doctor immediately.

Breast-feeding: Wellbutrin SR (Bupropion) passes into breast milk. Because Wellbutrin SR (Bupropion) presents risks to breast-feeding infants, a decision should be made whether to discontinue breast-feeding or to discontinue Wellbutrin SR (Bupropion), taking into account the importance of the medication to the mother. Talk to your doctor about whether you should continue breast-feeding. 

Children: The safety and effectiveness of Wellbutrin SR (Bupropion) have not been established for children and adolescents under 18 years old. The use of Wellbutrin SR (Bupropion) in children below the age of 18 may cause behavioural and emotional changes, such as suicidal thoughts and behaviour.

Seniors: Because Wellbutrin SR (Bupropion) is removed from the body by the kidney and liver, seniors may be at an increased risk of side effects, including seizures, if they use Wellbutrin SR (Bupropion). If you are over 65, discuss with your doctor whether any special monitoring is required.