Can Wellbutrin SR (bupropion) 150mg twice a day cause dry mouth, dizziness, and poor sleep in a 53-year-old male?

Wellbutrin SR 150mg BID Can Cause Dry Mouth, Dizziness, and Poor Sleep

Yes, Wellbutrin SR (bupropion) 150mg twice daily commonly causes all three of these side effects—dry mouth, dizziness, and poor sleep—in a 53-year-old male. These are well-documented adverse effects that occur frequently enough to be listed among the primary side effects in FDA labeling and clinical guidelines.

Evidence from FDA Drug Labeling

The FDA-approved prescribing information explicitly lists these symptoms as common side effects of bupropion extended-release formulations 1:

• Dry mouth is one of the most common side effects 1
• Dizziness is specifically listed as a common adverse effect 1
• Trouble sleeping is identified as a frequent side effect, with specific guidance that patients should not take bupropion too close to bedtime 1

Clinical Evidence Supporting These Side Effects

Dry Mouth (Xerostomia)

Dry mouth is one of the most consistently reported side effects of bupropion across all formulations. The American Gastroenterological Association confirms that bupropion causes dry mouth as a common side effect when used in combination formulations 2. Research studies demonstrate that dry mouth occurs significantly more frequently with bupropion SR than with placebo 3. In a controlled study of 24 subjects, there was a statistically significant main effect of bupropion on dry mouth (p < 0.049) 4.

Dizziness

Dizziness is a well-established neurological side effect of bupropion. The American College of Cardiology and other medical societies acknowledge that bupropion commonly causes dizziness along with other neurological effects 5. The American Gastroenterological Association lists dizziness among the common side effects in their obesity medication comparison table 2. However, one research study found no significant impact of bupropion SR on dizziness in their specific testing protocol 4, though this does not negate the broader clinical experience and FDA labeling.

Poor Sleep/Insomnia

Insomnia is one of the most prominent and frequently reported side effects of bupropion. The American Gastroenterological Association identifies insomnia as a common side effect across multiple bupropion-containing formulations 2. Clinical trials consistently show that insomnia occurs significantly more frequently with bupropion SR than with placebo 3. Research demonstrates a main effect of bupropion on "number of awakenings" (p < 0.048) and "difficulty returning to sleep" (p < 0.004) 4.

The timing of bupropion administration is critical for minimizing sleep disturbance. The American Academy of Family Physicians recommends taking the first dose in the morning and the second dose before 3 PM to minimize insomnia risk 6. This is because bupropion has activating properties that can interfere with sleep if taken too late in the day 6.

Frequency and Clinical Significance

These side effects are common enough that they appear in every major guideline and drug reference:

• In clinical trials for smoking cessation, the most common adverse events associated with bupropion SR 150mg twice daily included insomnia, headache, dry mouth, nausea, and anxiety 3
• Only insomnia and dry mouth occurred significantly more frequently with bupropion SR compared to placebo in controlled trials 3
• Discontinuation rates due to adverse events in clinical trials were relatively low (6-12%), suggesting these side effects are generally tolerable 3

Management Strategies

For dry mouth: The National Comprehensive Cancer Network recommends optimizing hydration, using saliva substitutes, and employing salivary stimulants such as sugar-free chewing gum 7. For severe cases, systemic sialagogues like pilocarpine may be considered 7.

For insomnia: Ensure the second dose is taken before 3 PM 6. If sleep disturbance persists, consider reducing the dose or switching to once-daily dosing 3. The FDA label specifically advises not taking bupropion too close to bedtime 1.

For dizziness: Monitor blood pressure and heart rate, especially during the first 12 weeks of treatment, as bupropion can cause cardiovascular effects including tachycardia that may contribute to dizziness 5.

Important Clinical Caveats

• These side effects are generally transient and often resolve quickly without therapeutic intervention 3
• They can be managed if necessary by a reduction in bupropion dose 3
• The benefits of bupropion for depression or smoking cessation should be weighed against these side effects 7
• Patients should be counseled that these are expected side effects and do not necessarily indicate a serious problem 1