Can buspirone (Buspar) be used in patients with epilepsy without lowering the seizure threshold?

Buspirone and Seizure Risk

Buspirone lowers the seizure threshold and should be avoided in patients with epilepsy or any condition predisposing to seizures. This is explicitly stated in major guidelines for targeted temperature management, where buspirone is listed among anti-shivering medications with the specific caveat that it "lowers seizure threshold" 1.

Evidence from Clinical Guidelines

The most authoritative evidence comes from the 2023 European Heart Journal guidelines on sedation and shivering management after cardiac arrest 1. These guidelines specifically warn that:

• Buspirone (30 mg every 8 hours) lowers seizure threshold when used as an anti-shivering agent 1
• The guidelines note this limitation explicitly in their medication comparison table, distinguishing it from other agents that lack this risk 1
• When combined with meperidine at high doses (30 mg buspirone), the combination can reduce shivering threshold to as low as 33°C, but "caution is advised for those at risk of seizure or those who are not continuously monitored" 1

Supporting Research Evidence

Research literature confirms this seizure risk:

• Buspirone lacks anticonvulsant properties entirely, unlike benzodiazepines, and does not provide any protective effect against seizures 2
• Case reports document seizures with buspirone overdose, including a generalized tonic-clonic seizure occurring 36 hours after ingestion 3
• A massive overdose case involving buspirone (along with lamotrigine and bupropion) resulted in status epilepticus requiring aggressive treatment with lorazepam, propofol, and phenobarbital 4
• Breakthrough seizures have been reported in patients with controlled epilepsy after starting medications with similar serotonergic mechanisms (5-HT1A partial agonists like vilazodone), suggesting this drug class may lower seizure threshold 5

Clinical Context and Mechanism

Buspirone's mechanism of action involves:

• Primary activity at 5-HT1A receptors with additional effects on DA2 autoreceptors and 5-HT2 receptors 2
• This serotonergic mechanism appears to have proconvulsive potential, particularly in patients with pre-existing seizure disorders 5
• The drug is fundamentally different from benzodiazepines, lacking their anticonvulsant and muscle-relaxant properties 2

Practical Recommendations

For patients with epilepsy:

• Avoid buspirone entirely due to documented seizure threshold lowering 1
• Consider alternative anxiolytics that do not lower seizure threshold 1
• If anxiety treatment is essential, benzodiazepines may be safer as they possess anticonvulsant properties 2

For patients without epilepsy but with seizure risk factors:

• Exercise extreme caution, as guidelines specifically warn about use in "those at risk of seizure" 1
• Risk factors include history of head trauma, brain tumor, stroke, or any condition predisposing to seizures 6
• Continuous monitoring is recommended if buspirone must be used in at-risk patients 1

Common pitfall to avoid:

• Do not assume buspirone is safe simply because seizures are rare at therapeutic doses—the risk is dose-dependent and significantly elevated in patients with pre-existing seizure disorders or risk factors 7, 3