What are common benzodiazepines (benzos) listed in order from shortest to longest half-life for a patient with anxiety or insomnia?

Common Benzodiazepines Listed by Half-Life (Shortest to Longest)

For anxiety and insomnia management, benzodiazepines should be selected based on their elimination half-life, with short-acting agents like triazolam (half-life <4 hours) and midazolam used for acute situations, intermediate-acting agents like lorazepam (8-15 hours) and temazepam (8.8 hours mean) for most clinical scenarios, and long-acting agents like diazepam (>20 hours) reserved for specific indications requiring sustained effect. 1, 2, 3

Ultra-Short Acting (Half-life <4 hours)

• Midazolam: Shortest duration of action among commonly used benzodiazepines, with more rapid onset but shorter duration than lorazepam, making it suitable for acute agitation requiring immediate effect 4
• Triazolam: Half-life <4 hours, recommended for sleep-onset insomnia at 0.125-0.25 mg, though carries greater risks of adverse effects including rebound insomnia and cognitive impairment due to rapid elimination and high receptor-binding affinity 1, 3, 5

Short-to-Intermediate Acting (Half-life 8-15 hours)

• Lorazepam: Terminal half-life approximately 8-15 hours, preferred for acute anxiety/agitation due to fast onset, rapid and complete absorption, no active metabolites, and lower risk of sedation; suitable for elderly patients 4, 1, 6
• Temazepam: Mean terminal half-life of 8.8 hours (range 3.5-18.4 hours), recommended for sleep-maintenance insomnia at 7.5-30 mg (start 7.5 mg in elderly), with intermediate GABA-A receptor affinity and minimal hangover effects 1, 6, 2
• Alprazolam: Intermediate half-life, widely used particularly in the US for panic disorder, though not recommended in the UK especially for long-term use due to dependence risks 7, 3, 8
• Oxazepam: Intermediate half-life with no active metabolites, preferred for elderly and debilitated patients alongside lorazepam and temazepam 1

Long-Acting (Half-life >20 hours)

• Diazepam: Half-life >20 hours with active metabolites, erratic absorption when given intramuscularly, suitable for single or intermittent dosing in anxiety and effective for insomnia in single doses, but should be avoided in elderly patients with liver disease due to accumulation risk 4, 1, 3
• Clonazepam: Long half-life, used for specific indications including epilepsy and may possess anti-panic and anti-manic properties, though carries risks of dependence and withdrawal with prolonged use 1, 3, 8

Critical Selection Principles

For Insomnia

• Sleep-onset insomnia: Use short-acting agents (triazolam, zaleplon) to minimize daytime sedation 1
• Sleep-maintenance insomnia: Use intermediate-acting agents (temazepam 7.5-30 mg, estazolam 0.5-2 mg) for sustained effect without excessive hangover 1, 2
• Prescriptions should be limited to a few days, occasional/intermittent use, or courses not exceeding 2 weeks maximum 1, 6, 3

For Anxiety/Agitation

• Acute situations: Lorazepam preferred due to predictable absorption and no active metabolites 4, 1
• Episodic anxiety: Diazepam in single doses or very short courses (1-7 days) 3
• Combination of benzodiazepine plus antipsychotic frequently recommended for acutely agitated patients 4

Special Population Considerations

• Elderly patients: Start with half the standard adult dose; prefer agents with shorter half-lives and no active metabolites (lorazepam, oxazepam, temazepam); avoid long-acting agents like diazepam entirely due to fall risk, cognitive impairment, and accumulation of active metabolites 1, 9
• Liver disease: Avoid diazepam and other long-acting agents due to prolonged sedation and delirium risk from metabolite accumulation 1

Duration and Safety Warnings

• All benzodiazepines should be prescribed for the shortest duration possible, ideally 2-4 weeks maximum, not exceeding 4 months 1, 6, 3
• Rapidly eliminated benzodiazepines (triazolam, midazolam) produce the most pronounced rebound and withdrawal syndromes 8, 5
• Never combine with opioids due to dangerous synergistic respiratory depression 1, 6
• Cognitive behavioral therapy should be the initial intervention for chronic insomnia, not benzodiazepines 1, 10