What are the side effects of Buspirone (anxiolytic medication)?

Side Effects of Buspirone

The most common side effects of buspirone are dizziness (12%), drowsiness (10%), nausea (8%), headache (6%), nervousness (5%), and lightheadedness (3%), with these effects generally well-tolerated and rarely requiring discontinuation of treatment. 1

Most Frequently Reported Side Effects

Central Nervous System Effects

• Dizziness occurs in 12% of patients, making it the most common side effect, compared to 3% with placebo 1
• Drowsiness affects 10% of patients (versus 9% with placebo) 1
• Nervousness occurs in 5% of patients 1
• Lightheadedness affects 3% of patients 1
• Insomnia occurs in 3% of patients 1
• Excitement affects 2% of patients 1

Gastrointestinal Effects

• Nausea occurs in 8% of patients (versus 5% with placebo), making it the most common gastrointestinal side effect 1
• Dry mouth affects 3% of patients 1
• Abdominal or gastric distress occurs in 2% of patients 1
• Diarrhea, constipation, and vomiting each occur in 1-2% of patients 1

Other Common Effects

• Headache occurs in 6% of patients (versus 3% with placebo) 1
• Fatigue affects 4% of patients 1
• Weakness occurs in 2% of patients 1

Discontinuation Rates Due to Side Effects

• Approximately 10% of patients discontinued buspirone during clinical trials due to adverse events 1
• The most common reasons for discontinuation were:
  • Central nervous system disturbances (3.4%), primarily dizziness, insomnia, nervousness, drowsiness, and lightheadedness 1
  • Gastrointestinal disturbances (1.2%), primarily nausea 1
  • Miscellaneous disturbances (1.1%), primarily headache and fatigue 1

Less Common but Notable Side Effects

Cardiovascular Effects

• Tachycardia and palpitations occur in 1% of patients 1
• Infrequent effects include syncope, hypotension, and hypertension 1
• Rare but serious cardiovascular events include cerebrovascular accident, congestive heart failure, myocardial infarction, cardiomyopathy, and bradycardia 1

Neuropsychiatric Effects

• Dream disturbances occur frequently 1
• Infrequent effects include depersonalization, dysphoria, euphoria, akathisia, fearfulness, hallucinations, involuntary movements, slowed reaction time, suicidal ideation, and seizures 1
• Rare but serious movement disorders have been reported, including dystonia, dyskinesias (both acute and tardive), extrapyramidal symptoms, parkinsonism, akathisia, and restless leg syndrome 1, 2

Other Organ Systems

• EENT effects: Tinnitus, sore throat, nasal congestion occur frequently; blurred vision affects 2% of patients 1
• Musculoskeletal effects: Muscle aches/pains occur in 1% of patients 1
• Skin effects: Rash occurs in 1% of patients 1

Important Clinical Considerations

Tolerability Profile

• Buspirone is generally well-tolerated with minimal sedation, unlike benzodiazepines 3, 4
• The drug does not cause anticonvulsant or muscle-relaxant effects 3
• Buspirone does not impair psychomotor function or interact significantly with alcohol 3, 4
• No abuse, dependence, or withdrawal symptoms have been reported 3, 4

Serious Adverse Events

• Persistent movement disorders can occur, including cervical-cranial dystonia and exacerbation of preexisting movement disorders, particularly with prolonged use at doses of 30-40 mg/day 2
• Serotonin syndrome has been reported in postmarketing surveillance 1
• Allergic reactions including urticaria and angioedema are rare 1

Monitoring Recommendations

• Buspirone takes 2-4 weeks to become effective, so early side effects should be monitored during this period 5
• The initial dosage typically starts at 5 mg twice daily, with a maximum recommended dosage of 20 mg three times daily 5
• Patients should be monitored for emergence of movement disorders, particularly with prolonged use 2