Thienodiazepines

Benzodiazepines with the fused benzene ring replaced by a thiophene. The swap is a genuine structural distinction, which is why they are their own family on the second axis, but the pharmacology is continuous with the benzodiazepines: the same GABA-A benzodiazepine site, the same cross-tolerance, the same additive respiratory depression with opioids and alcohol, the same seizure risk in withdrawal. Everything written on the benzodiazepine page applies here.

Etizolam is a licensed medicine in a few countries and a research chemical everywhere else, which is how it came to dominate counterfeit tablets; deschloroetizolam, metizolam, brotizolam, flubrotizolam and fluclotizolam followed it out of the same market. Several members are potent and long-lasting, and tablets sold as alprazolam or diazepam routinely contain one of them instead — so the name pressed into a tablet predicts neither which drug it is nor how long it will last.