Class Explorer · Psychiatry
Benzodiazepines and Z-drugs
Positive allosteric modulators at GABA-A: they do not open the channel themselves, they make the body's own GABA more effective. That distinction is why they are safer alone than barbiturates and still lethal with opioids.
Members
LorazepamThe benzodiazepine the liver does not have to think about.ZopicloneA hypnotic marketed as safer than a benzodiazepine, on evidence that has not held up.
Also in this class: Diazepam · Midazolam · Clonazepam · Zolpidem. Full pages arrive as the library grows.
Compare the members
Shared across the class
- Indications
- Short-term anxiety or insomnia · Alcohol withdrawal · Status epilepticus · Procedural sedation
- Adverse effects
- Sedation · Falls and fractures in older adults · Anterograde amnesia · Tolerance and dependence · Respiratory depression with opioids
- Contraindications
- Severe respiratory failure · Untreated obstructive sleep apnoea, relative
- Monitoring
- Sedation and gait, especially in the first week and in older adults · Duration of use, which is the real safety variable · Co-prescribed opioids
What makes each agent different
- Lorazepam is intermediate-acting, glucuronidated rather than oxidised, and therefore the safest choice in liver disease and in older adults.
- Diazepam is long-acting with active metabolites that accumulate for days: excellent for a smooth alcohol withdrawal, poor for an 85-year-old's insomnia.
- Z-drugs are structurally different but act at the same receptor, and the claim that they are meaningfully safer has not survived contact with fracture and next-morning-impairment data.
Every benzodiazepine prescription should be written with its end date already decided, because the drug is far easier to start than to stop.
Withdrawal is not a nuisance, it is a seizure risk. Long-term use is tapered over months, not stopped.
Last reviewed 2026-08-16 · Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed.