Between the two medications usually used during a seizure, which has the longer half-life?

• A. Diazepam (Valium)
• B. Midazolam (Versed)
• C. Lorazepam (Ativan)
• D. Alprazolam (Xanax)

Answer: (A)

When considering how long a drug continues to exert effects, half-life matters: it’s the time it takes for the plasma concentration to drop by half. Among the benzodiazepines commonly used in seizure management, diazepam stays in the body longer because it is highly lipophilic and is metabolized into active products that persist for a long time (desmethyldiazepam and other metabolites). This combination of rapid brain entry and long-lasting metabolites extends the overall elimination time, so diazepam has the longer half-life in comparison to its fellow seizure-fighting option. Lorazepam, while effective for stopping a seizure and often preferred in a hospital setting for its steadier action, is conjugated and does not produce long-acting metabolites, leading to a shorter half-life. Midazolam works quickly but has a much shorter half-life due to rapid metabolism, and alprazolam isn’t typically used acutely for seizures.