Do benzodiazepines (benzos) lower the seizure threshold?

From the Guidelines

Benzodiazepines (benzos) actually raise the seizure threshold, not lower it, making them effective medications for treating and preventing seizures. Commonly used benzodiazepines for seizure management include diazepam (Valium), lorazepam (Ativan), clonazepam (Klonopin), and midazolam. For acute seizures, lorazepam is often given at 2-4mg IV, while diazepam may be administered at 5-10mg IV. For maintenance therapy, clonazepam is typically prescribed at 0.5-2mg twice daily. Benzodiazepines work by enhancing the effect of gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain, which reduces neuronal excitability and prevents the abnormal electrical activity that causes seizures.

Key Points to Consider

• The use of benzodiazepines in seizure management is supported by recent guidelines, including the 2024 clinical policy on critical issues in the management of adult patients presenting to the emergency department with seizures 1.
• However, abrupt discontinuation of benzodiazepines after prolonged use can paradoxically lower the seizure threshold and potentially trigger withdrawal seizures, even in people without a history of epilepsy 1.
• This is why benzodiazepines should always be tapered gradually when discontinuing treatment, typically reducing the dose by 10-25% every 1-2 weeks depending on the patient's response and the duration of previous use.
• Other substances, such as tramadol and cocaine, can lower the seizure threshold, and benzodiazepines may be used to manage seizures in these cases 1.
• The benefits of benzodiazepine use in seizure management include a reduction in morbidity and mortality, while the harms are limited to the potential for an adverse drug reaction 1.

From the Research

Benzodiazepines and Seizure Threshold

• The provided studies do not directly address whether benzodiazepines lower the seizure threshold. However, they discuss the use of benzodiazepines in the treatment of seizures and status epilepticus 2, 3, 4, 5.
• One study mentions that antipsychotic medications, not benzodiazepines, can lower the seizure threshold, increasing the chances of seizure induction 6.
• Benzodiazepines are commonly used as anticonvulsants and are the first-line treatment for status epilepticus, suggesting that they may actually help raise the seizure threshold or prevent seizures rather than lower it 2, 3, 4.
• The studies focus on the efficacy, tolerability, and administration of benzodiazepines in the treatment of seizures and status epilepticus, rather than their potential to lower the seizure threshold 2, 3, 4, 5.

Administration and Efficacy of Benzodiazepines

• Benzodiazepines can be administered through various routes, including intravenous, intramuscular, rectal, intranasal, and buccal 2, 3, 4, 5.
• The choice of benzodiazepine and route of administration depends on the specific patient population and the severity of the seizure or status epilepticus 2, 3, 4, 5.
• Studies have shown that benzodiazepines are effective in the treatment of seizures and status epilepticus, with different benzodiazepines having different efficacy profiles and pharmacokinetic properties 2, 3, 4, 5.