Systematic (IUPAC) name
7-chloro-3-methyl-3,4-dihydro-2H-1,2,4-benzothiadiazine 1,1-dioxide
Clinical data
Legal status
  • Investigational New Medicine
CAS Registry Number  YesY
PubChem CID:
Synonyms IDRA-21
Chemical data
Formula C8H9ClN2O2S
Molecular mass 232.68726 g/mol

IDRA-21 is an ampakine drug and a benzothiadiazine derivative. IDRA-21 is a chiral molecule, with (+)-IDRA-21 being the active form.[1]

IDRA-21 shows nootropic effects in animal studies, significantly improving learning and memory. It is around 10-30x more potent than aniracetam in reversing cognitive deficits induced by alprazolam or scopolamine,[2][3] and produces sustained effects lasting for up to 48 hours after a single dose.[4] The mechanism for this action is thought to be through promoting the induction of long-term potentiation between synapses in the brain.[5]

IDRA-21 does not produce neurotoxicity under normal conditions,[6] although it may worsen neuronal damage following global ischemia after stroke or seizures.[7]

In comparison to the benzoylpiperidine derived ampakine drugs, IDRA-21 was more potent than CX-516, but less potent than CX-546.[8] Newer benzothiadiazide derivatives with greatly increased potency compared to IDRA-21 have been developed,[9][10] but these have not been researched to the same extent, with the benzoylpiperidine and benzoylpyrrolidine CX- series of drugs being favoured for clinical development, most likely due to more favourable toxicity profiles at high doses.[11]

See also


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