What are the side effects of Buspar (buspirone), particularly regarding dreams?

Side Effects of Buspirone (Buspar)

Buspirone commonly causes dream disturbances, which are listed as a frequent central nervous system side effect in the FDA drug label. 1

Common Side Effects

Buspirone's side effect profile differs significantly from other anxiolytics like benzodiazepines. The most commonly reported side effects include:

• Central Nervous System Effects:

  • Dizziness (12% vs 3% for placebo) 1
  • Drowsiness (10% vs 9% for placebo) 1
  • Nervousness (5% vs 1% for placebo) 1
  • Lightheadedness (3%) 1
  • Dream disturbances (frequent occurrence) 1
  • Headache (6% vs 3% for placebo) 1

• Gastrointestinal Effects:

  • Nausea (8% vs 5% for placebo) 1
  • Dry mouth (3% vs 4% for placebo) 1
  • Abdominal/gastric distress (2% vs 2% for placebo) 1

Dream-Related Side Effects

The FDA drug label specifically lists "dream disturbances" as a frequent central nervous system side effect 1. This means it occurs in at least 1/100 patients taking buspirone. These dream disturbances may include:

• Vivid dreams
• Unusual dreams
• Abnormal dreams
• Nightmares

Discontinuation Rates

Approximately 10% of patients in clinical trials discontinued buspirone due to adverse effects 1. The most common reasons for discontinuation were:

• CNS disturbances (3.4%) - including dizziness, insomnia, nervousness, drowsiness, and lightheaded feeling
• Gastrointestinal disturbances (1.2%) - primarily nausea
• Miscellaneous disturbances (1.1%) - primarily headache and fatigue

Comparison to Other Anxiolytics

Unlike benzodiazepines, buspirone:

• Does not cause significant sedation 2
• Lacks anticonvulsant and muscle-relaxant properties 2
• Does not impair driving skills 3
• Does not interact with alcohol 3
• Does not produce physiological dependence 3
• Has minimal abuse potential 3

Dosing Considerations

The typical dosing of buspirone is 15-30 mg per day, divided into multiple doses 1. A meta-analysis comparing twice-daily (15 mg BID) versus three-times-daily (10 mg TID) dosing found similar side effect profiles, except for a higher incidence of palpitations with the BID regimen (5% vs 1%) 4.

Long-Term Safety

Long-term use of buspirone (up to one year) has not been associated with the emergence of new or unexpected side effects beyond those reported during shorter treatment periods 5. Additionally, abrupt discontinuation after more than six months of therapy did not produce withdrawal symptoms 5.

Mechanism and Unique Properties

Buspirone's side effect profile is related to its unique mechanism of action as a 5-HT1A partial agonist 6. Unlike benzodiazepines, which enhance GABA activity, buspirone primarily affects serotonin systems, with some effects on dopamine D2 autoreceptors 6. This explains why it produces different side effects than benzodiazepines.

Clinical Implications

When prescribing buspirone:

• Inform patients about possible dream disturbances
• Reassure patients that these effects are generally not harmful
• Consider timing of doses if dream disturbances are bothersome (morning/afternoon dosing may be preferable to evening dosing)
• Monitor for other common side effects like dizziness and nausea
• Remind patients that unlike benzodiazepines, buspirone takes 2-4 weeks to reach full therapeutic effect 7

If dream disturbances become problematic, dosage adjustment or alternative medication may be considered, but these effects are generally not a reason to discontinue therapy unless they significantly impact sleep quality or cause distress.