Side Effects of Wellbutrin (Bupropion)
Wellbutrin commonly causes dry mouth, insomnia, headache, nausea, and constipation, with the most serious risk being seizures occurring at a rate of 1 in 1,000 patients, particularly in those with predisposing factors. 1
Common Side Effects
The most frequently reported adverse effects include:
Neurological effects: Insomnia, headache, dizziness, and tremor are among the most common complaints 1. Insomnia can be managed by avoiding doses close to bedtime 2.
Gastrointestinal effects: Dry mouth, nausea, constipation, and vomiting occur frequently 1. Dry mouth is particularly common and can create a sensation of something stuck in the throat due to reduced saliva production 3. Increasing water intake throughout the day helps manage this symptom 3.
Other common effects: Anxiety, stuffy nose, joint aches, and feeling anxious are reported 2. Drowsiness and dizziness may also occur 4.
Tolerability: Only insomnia and dry mouth occur significantly more frequently with bupropion compared to placebo 5. These effects are generally transient and often resolve quickly without intervention 5.
Serious Side Effects Requiring Immediate Attention
Seizures
Risk profile: Seizures occur at a rate of approximately 1 in 1,000 patients (0.1%) when properly dosed at 300 mg/day or less 1, 5.
Risk factors that increase seizure likelihood: Prior history of seizures, structural brain lesions from stroke/tumor/trauma, alcohol abuse, eating disorders, recent discontinuation of alcohol/benzodiazepines/barbiturates/antiepileptic drugs, and concomitant medications that lower seizure threshold 1.
Critical dosing considerations: The maximum daily dose is 300 mg for extended-release formulations, with doses taken at least 24 hours apart 2. Never crush, chew, or cut tablets, as this releases medication too quickly and increases seizure risk 2.
Action required: If a seizure occurs, stop bupropion immediately and do not restart 2.
Psychiatric and Behavioral Changes
Suicidal thoughts and behavior: Monitor closely for new or worsening depression, suicidal thoughts or actions, anxiety, agitation, panic attacks, irritability, aggression, hostility, or mania 2. This risk is particularly elevated in young adults and those with bipolar disorder or history of mental health problems 2.
Timing: Symptoms may appear when starting treatment, after several weeks, or even after stopping bupropion 2. Some symptoms may persist after discontinuation, requiring continued follow-up 2.
Action required: Stop bupropion and call your healthcare provider immediately if these symptoms develop 2.
Cardiovascular Effects
Hypertension: Some patients develop high blood pressure that can be severe, especially when combined with nicotine replacement therapy 2. Blood pressure and heart rate should be monitored periodically, particularly during the first 12 weeks of treatment 1.
Tachycardia: Heart rate increases and tachyarrhythmias can occur, ranging from mild to severe 1.
Hypersensitivity Reactions
Delayed allergic reactions: Severe hypersensitivity reactions occur in approximately 0.1% of patients 5. These can include itchiness, urticaria (hives), and pruritus that may appear 2 or more weeks after starting treatment 6.
Risk factors: Males aged 17-40 years and those with a history of allergic reactions may be at higher risk 6.
Action required: If severe or persistent throat sensations, difficulty swallowing, or allergic symptoms develop, seek medical evaluation 3.
Special Precautions and Contraindications
Absolute Contraindications
Never use with MAOIs: Risk of hypertensive crisis 1.
Avoid in patients with: History of seizures, eating disorders (bulimia/anorexia), uncontrolled hypertension, or conditions predisposing to seizures 1.
Alcohol Considerations
- Limit or avoid alcohol during treatment 2. If you regularly drink large amounts of alcohol, do not suddenly stop, as this increases seizure risk 2. Discuss alcohol use with your provider before starting bupropion 2.
Drug Interactions
Bupropion inhibits cytochrome P450 2D6 enzyme, requiring caution with drugs metabolized by this pathway 7.
Many medications increase seizure risk when combined with bupropion 2. Do not start new medications without checking with your provider 2.
Manic Episodes
- Patients with bipolar disorder or family history of bipolar illness are at risk for manic episodes, characterized by extreme increases in activity and talking 2.
Discontinuation Rate and Overall Tolerability
Bupropion is generally well tolerated, with discontinuation rates due to adverse events ranging from only 6-12% in clinical trials 5.
The medication produces no significant changes in mean heart rate, blood pressure, or routine laboratory parameters when used alone at recommended doses 5.
Most common side effects resolve within 4-5 days after starting treatment 4.
Important Safety Notes
False positive drug tests: Bupropion may cause urine drug screening tests to show positive for amphetamines 2. Inform testing personnel that you take bupropion for more specific testing 2.
Driving and machinery: Do not drive or use heavy machinery until you know how bupropion affects you 2.
Pregnancy and age: Safety and effectiveness in children under 18 years have not been established 2.