From the Guidelines
Buspar (buspirone) can cause several side effects, including dizziness, headache, nervousness, lightheadedness, nausea, and sometimes excitement or restlessness, but it is generally well-tolerated and has a more favorable side effect profile compared to other anxiolytic drugs.
Common Side Effects
- Dizziness
- Headache
- Nervousness
- Lightheadedness
- Nausea
- Excitement or restlessness Some patients may also experience drowsiness, fatigue, or insomnia, while less common side effects may include dry mouth, blurred vision, diarrhea, and muscle pain 1.
Serious Side Effects
Serious side effects are rare but can include serotonin syndrome (especially when combined with other serotonergic medications), allergic reactions, or movement disorders.
Minimizing Side Effects
Most side effects are mild and often diminish after the first few weeks of treatment as your body adjusts to the medication. Starting with a low dose (typically 5mg twice daily) and gradually increasing to the therapeutic range (15-30mg daily in divided doses) can help minimize side effects, as recommended in the guidelines for managing behavior and mood disorders 1.
Comparison to Other Anxiolytic Drugs
Unlike benzodiazepines, Buspar doesn't cause significant physical dependence or withdrawal symptoms and has minimal impact on cognitive function, making it a preferred anxiety treatment for many patients, especially considering the potential risks associated with typical antipsychotic agents and other mood-stabilizing drugs 1.
From the FDA Drug Label
ADVERSE REACTIONS (See also PRECAUTIONS) Commonly Observed The more commonly observed untoward events associated with the use of buspirone hydrochloride tablets not seen at an equivalent incidence among placebo-treated patients include dizziness, nausea, headache, nervousness, lightheadedness, and excitement The table that follows enumerates adverse events that occurred at a frequency of 1% or more among buspirone hydrochloride patients who participated in 4-week, controlled trials comparing buspirone hydrochloride tablets with placebo TREATMENT-EMERGENT ADVERSE EXPERIENCE INCIDENCE IN PLACEBO-CONTROLLED CLINICAL TRIALS* (Percent of Patients Reporting) Adverse ExperienceBuspirone hydrochloride (n = 477)Placebo (n = 464)
- Incidence less than 1%. * Events reported by at least 1% of buspirone hydrochloride patients are included Cardiovascular Tachycardia/Palpitations1 CNS Dizziness12 Drowsiness10 Nervousness5 Insomnia3 Lightheadedness3 Decreased concentration2 Excitement2 Anger/Hostility2 Confusion2 Depression2 EENT Blurred vision2 Gastrointestinal Nausea8 Dry mouth3 Abdominal/gastric distress2 Diarrhea2 Constipation1 Vomiting1 Musculoskeletal Musculoskeletal aches/pains1 Neurological Numbness2 Paresthesia1 Incoordination1 Tremor1 Skin Skin rash1 Miscellaneous Headache6 Fatigue4 Weakness2 Sweating/Clamminess1
The common side effects of Buspar include:
- Dizziness (12%)
- Nausea (8%)
- Headache (6%)
- Nervousness (5%)
- Lightheadedness (3%)
- Insomnia (3%)
- Drowsiness (10%)
- Fatigue (4%) 2
From the Research
Buspar Side Effects
- The frequency of adverse effects of Buspar is low, with the most common effects being headaches, dizziness, nervousness, and lightheadness 3
- Sedation occurs much less often after Buspar than after the benzodiazepines; other side effects are minor and infrequent 4
- Buspar does not impair psychomotor or cognitive function, and appears to have no additive effect with alcohol 4
- Abuse, dependence, and withdrawal symptoms have not been reported 3
- The pharmacokinetics of Buspar were not affected by age or gender, but administration with food increased the Cmax and area under the plasma concentration-time curve (AUC) of Buspar 2-fold 5
- Coadministration of Buspar with verapamil, diltiazem, erythromycin and itraconazole substantially increased the plasma concentration of Buspar, whereas cimetidine and alprazolam had negligible effects 5
- Rifampicin (rifampin) decreased the plasma concentrations of Buspar almost 10-fold 5
Special Considerations
- Patients with renal impairment had a 2-fold increase in Cmax and AUC of Buspar compared to healthy volunteers 5
- Patients with hepatic impairment had a 15-fold higher Cmax and AUC of Buspar compared to healthy individuals, and the half-life of Buspar was twice that in healthy individuals 5
- Buspar may be useful in various other neurological and psychiatric disorders, such as attenuating side effects of Parkinson's disease therapy, ataxia, depression, social phobia, and behaviour disturbances following brain injury, and those accompanying Alzheimer's disease, dementia and attention deficit disorder 6