Bromazolam
Bromazolam is a designer triazolobenzodiazepine, the brominated analogue of alprazolam. First synthesised in the 1970s but never marketed as a medicine, it re-emerged as one of the most commonly detected designer benzodiazepines in the 2020s, frequently in counterfeit tablets and in combination with fentanyl in overdose deaths.
01 Overview
Bromazolam is closely related to alprazolam, differing by a bromine substitution, and produces a comparable sedative-anxiolytic profile. Its potency is broadly in the alprazolam range. As with the rest of this class there are no human clinical trials; the data are forensic, from poison-centre calls and seized-drug surveillance where its detection rate has risen sharply.
It is often found in illicit 'benzo' tablets sold as alprazolam and, increasingly, mixed with synthetic opioids. The public-health concern is precisely this polydrug context: bromazolam adds sedation and respiratory depression on top of fentanyl, and does not respond to naloxone.
02 Mechanism
Positive allosteric modulator at the GABA-A benzodiazepine site; triazolobenzodiazepine structure analogous to alprazolam.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Threshold | 0.25–0.5 mg | Oral | Roughly alprazolam-like potency; anecdotal figures only. |
| Common | 0.5–1.5 mg | Oral | Content of illicit tablets is highly variable and often unknown. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Anxiolysis and sedationAnxiety reduction with drowsiness, typical of alprazolam-like compounds. | Anecdotal | ||
| Muscle relaxationSkeletal muscle relaxation. | Anecdotal | ||
| Euphoria and disinhibitionReported mild euphoria and disinhibition motivating misuse. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Amnesia and impaired judgementBlackouts and impaired decision-making, compounded by unknown tablet content. | Moderate | Common at higher doses | Anecdotal | |
| Dependence and withdrawalPhysical dependence with rebound anxiety, insomnia and seizure risk on withdrawal. Cross-tolerant with all benzodiazepines. | Severe | Universal with regular use | Observational | |
| Respiratory depression in combinationIncreasingly detected alongside fentanyl in fatal overdoses; adds sedation and respiratory depression that naloxone does not reverse. | Life-threatening | Common in fentanyl-era overdoses | Observational |