Etazolate (SQ-20,009, EHT-0202) is an anxiolytic drug which is a pyrazolopyridine derivative and has unique pharmacological properties. It acts as a positive allosteric modulator of the GABA<sub>A</sub> receptor at the barbiturate binding site, as an adenosine antagonist of the A<sub>1</sub> and A<sub>2</sub> subtypes, and as a phosphodiesterase inhibitor selective for the PDE4 isoform. It is currently in clinical trials for the treatment of Alzheimer's disease.