Side Effects of Buspirone (Buspar)
The most common side effects of buspirone include dizziness, nausea, headache, nervousness, lightheadedness, and excitement, occurring in approximately 10% of patients. 1
Common Side Effects
Buspirone's side effect profile differs significantly from other anxiolytics like benzodiazepines. According to FDA data, the most frequently reported adverse events include:
Central Nervous System Effects:
- Dizziness (12% vs 3% placebo)
- Drowsiness (10% vs 9% placebo)
- Nervousness (5% vs 1% placebo)
- Insomnia (3% vs 3% placebo)
- Lightheadedness (3%)
- Decreased concentration (2% vs 2% placebo)
Gastrointestinal Effects:
- Nausea (8% vs 5% placebo)
- Dry mouth (3% vs 4% placebo)
- Abdominal/gastric distress (2% vs 2% placebo)
Other Common Effects:
- Headache (6% vs 3% placebo)
- Fatigue (4% vs 4% placebo)
Less Common Side Effects
Buspirone may also cause these less frequent adverse effects 1:
- Cardiovascular: Nonspecific chest pain (frequent); syncope, hypotension, hypertension (infrequent)
- CNS: Dream disturbances (frequent); depersonalization, dysphoria, euphoria, akathisia (infrequent)
- EENT: Tinnitus, sore throat, nasal congestion (frequent)
- Gastrointestinal: Flatulence, anorexia, increased appetite (infrequent)
- Sexual Function: Decreased or increased libido (infrequent); delayed ejaculation and impotence (rare)
- Skin: Edema, pruritus, flushing (infrequent)
Discontinuation Rate
Approximately 10% of patients discontinue buspirone due to adverse effects, with the most common reasons being 1:
- CNS disturbances (3.4%) - primarily dizziness, insomnia, nervousness
- Gastrointestinal disturbances (1.2%) - primarily nausea
- Miscellaneous (1.1%) - primarily headache and fatigue
Safety Advantages Compared to Benzodiazepines
Buspirone offers several safety advantages over benzodiazepines 2:
- No significant cognitive or motor impairment
- Does not potentiate effects of alcohol or other CNS depressants
- No abuse potential or physical dependence
- No withdrawal syndrome when discontinued after long-term use
- No anticonvulsant or muscle relaxant properties
- Minimal sedation
Dosing Considerations and Side Effect Management
The average effective dose is 20mg daily, typically given as 10mg twice daily or 15mg twice daily 3. A study comparing dosing regimens found similar adverse event profiles between twice-daily and three-times-daily dosing, with only palpitations occurring more frequently with twice-daily dosing (5% vs 1%) 3.
Important Precautions
Rare but serious adverse events reported in post-marketing surveillance include 1:
- Allergic reactions including urticaria
- Angioedema
- Extrapyramidal symptoms
- Serotonin syndrome
- Parkinsonism
- Akathisia
- Restless leg syndrome
Conclusion
Buspirone has a favorable side effect profile compared to many other anxiolytics, particularly benzodiazepines. Most side effects are mild and transient, with dizziness, nausea, headache, and nervousness being most common. The lack of sedation, cognitive impairment, dependence potential, and withdrawal symptoms makes it a particularly useful option for many patients with anxiety disorders.