The effects on memory of pipequaline, alone or in combination with diazepam

Pipequaline (PK 8165) is a putative mixed agonist/antagonist at benzodiazepine receptors. The effects of pipequaline and diazepam on memory were assessed in 12 normal volunteers. Diazepam 10 mg or placebo was added to two doses of pipequaline, 50 and 150 mg, or to placebo in a double-blind crossover design. Diazepam produced impairments of episodic memory. In contrast, the effects of pipequaline were minor. Addition diazepam to pipequaline increased drowsiness and general lethargy, with a less marked effect occurring for the higher dose of pipequaline alone. Pipequaline did not antagonise any of the effects of diazepam.