Designer benzodiazepine, Triazolobenzodiazepine, Sedative-Hypnotic, Research material
Bromazolam
(none — never marketed)
Bromazolam is a triazolobenzodiazepine first synthesized by Upjohn in 1976 and never developed clinically. It emerged on the research-chemical market around 2016 and, beginning around 2021–2022, became one of the most commonly encountered designer benzodiazepines in North America — notably as an adulterant in the illicit opioid supply alongside fentanyl and, often, xylazine. Pharmacologically and structurally it is the bromine analog of alprazolam, with comparable potency and a similar (or somewhat longer) duration of action.
No therapeutic dosing. Harm-reduction note: because of inconsistent tablet purity and frequent fentanyl co-contamination, any illicit "benzo" tablet should be assumed to potentially contain bromazolam, fentanyl, or both.
Sedation, anxiolysis, anterograde amnesia, ataxia, slurred speech, disinhibition, prolonged blackouts. At high dose or in combination: severe sedation, respiratory depression, coma. Paradoxical agitation/aggression occasionally reported. Withdrawal mirrors other high-potency benzos: anxiety, insomnia, autonomic hyperactivity, seizures, delirium — and can be life-threatening, often more protracted than alprazolam withdrawal owing to the longer half-life.
Lipophilic; orally bioavailable; hepatic metabolism (CYP3A4 predominantly) with hydroxylated metabolites. Half-life appears longer than alprazolam, with case reports of detection in blood/urine for days after a single exposure. Standard benzodiazepine immunoassay screens frequently miss bromazolam — confirmatory LC-MS/MS is required for reliable detection.
Pharmacodynamics
Non-selective positive allosteric modulator at the benzodiazepine site of GABAA receptors containing α1, α2, α3, or α5 subunits with a γ subunit. Like alprazolam, clinically displays anxiolytic, hypnotic, anticonvulsant, amnestic, and muscle-relaxant effects with significant abuse liability. Respiratory depression at high doses is modest in isolation but markedly synergized by opioids, alcohol, and other CNS depressants — the dominant mechanism of bromazolam-associated mortality.
Xylazine: frequently co-encountered in illicit opioid supply ("tranq dope"); compounds sedation and complicates resuscitation (xylazine is not reversed by naloxone).
CYP3A4 inducers (rifampin, carbamazepine, phenytoin, St John's wort): may reduce levels.
Flumazenil reverses GABAA effects but is rarely used in mixed-overdose / chronic-benzo contexts due to seizure risk.
Pregnancy and lactation
Avoid in pregnancy and lactation. Class data extrapolated from clinical benzodiazepines; designer status means no formal safety data.
Monitoring
In suspected overdose: airway, respiratory rate, oxygen saturation, mental status. Standard urine benzodiazepine immunoassay is insensitive to bromazolam — request specific LC-MS/MS confirmation. ECG and electrolytes if mixed overdose suspected.
Patient counseling
Patients should be counseled that illicit "Xanax bars" or designer benzodiazepine tablets are frequently bromazolam and/or fentanyl. Never combine with opioids or alcohol. Withdrawal requires medically supervised taper — do not stop abruptly after sustained use. Carry naloxone if any opioid co-use is plausible (naloxone does not reverse bromazolam itself but reverses concurrent opioid depression).
Oral, sublingual, intranasal; rectal and IV reported.
Onset
~20–40 min PO; faster sublingual/intranasal.
Duration
6–10 h subjective; full pharmacologic effect considerably longer.
Half-life
Estimated ~12–17 h (some sources cite up to ~21 h); active metabolites prolong effect.
Bioavailability
Not formally characterized in humans.
Pregnancy
Avoid. Benzodiazepines are associated with neonatal sedation, floppy-infant syndrome, and withdrawal; teratogenic signal weak but non-zero. Designer benzo with no safety data — assume worst-case.
Legal status
First synthesized by Upjohn in 1976; never marketed. Schedule I in several U.S. states (e.g., Virginia, Florida, Mississippi, Alabama); federally unscheduled in the U.S. as of mid-2020s but DEA has listed it as a med of concern. Class C in the UK (generic benzodiazepine controls). Controlled in Sweden, Germany (NpSG), Switzerland, and Canada.
Purported mechanism
Positive allosteric modulator of the GABAA receptor at the benzodiazepine binding site; increases frequency of Cl− channel opening, producing anxiolytic, sedative, hypnotic, anticonvulsant, and skeletal-muscle relaxant effects.