Bentazepam
Bentazepam is a thienodiazepine (a benzodiazepine analogue with a thiophene ring) that has seen limited use as an anxiolytic, historically in Spain. It is a GABA-A positive allosteric modulator producing anxiolysis and sedation. It is included here because it circulates on the grey market outside its limited licensed use.
01 Overview
Bentazepam belongs to the thienodiazepine subgroup, the same structural family as etizolam, and was used clinically as a short-acting anxiolytic in a small number of markets. Reports of hepatotoxicity contributed to its limited use.
Human pharmacological data are sparse and mostly old. Grey-market material is of uncertain purity, and the compound carries the usual benzodiazepine liabilities of dependence, tolerance and withdrawal, plus a notable signal for liver injury.
02 Mechanism
Thienodiazepine positive allosteric modulator at the GABA-A benzodiazepine site, enhancing GABAergic inhibition.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 10–25 mg | Oral | Lower dosing. |
| Common | 25–75 mg | Oral | Reflects historical anxiolytic dosing. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| AnxiolysisAnxiety reduction typical of benzodiazepines. | Anecdotal | ||
| SedationDrowsiness and CNS depression. | Anecdotal | ||
| Muscle relaxationSkeletal muscle relaxation. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Dependence and withdrawalTolerance, dependence and withdrawal including rebound anxiety and seizure risk. | Severe | Common with regular use | Anecdotal | |
| HepatotoxicityCase reports of liver injury associated with bentazepam use. | Severe | Rare but reported | Observational | |
| Respiratory depressionDepressed respiration, greatly increased with opioids or alcohol. | Life-threatening | Uncommon alone, higher with CNS depressants | Anecdotal |