Piperilate, also known as Pipethanate, is a hetrazepine derivative PAF antagonist and anticholinergic mixture, commonly utilized in bronchial asthma research. This compound exhibits hypotensive properties and has been found to effectively counteract the toxic effects of organophosphates in mice [1] [2] [3].

Piperilate administered at dosages of 11.3 mg/kg and 29.42 mg/kg via intraperitoneal injection (i.p.; single dose) in male albino mice (18-22 g), demonstrated notable anticholinergic properties, effectively antagonizing oxotremorine-induced salivation and tremors with EC50 values of 11.33 mg/kg and 29.42 mg/kg, respectively. At a higher dose of 30 mg/kg (i.p.; single dose), it exhibited protective efficacy in mice poisoned by organophosphates. Additionally, piperilate at 1 mg/kg through intravenous injection (i.v.) induced hypotension in rabbits without being affected by dichloroisoproterenol or Atropine. Furthermore, a 3 mg/kg (i.v.) dose reduced respiration and heart rate in rabbits, and blocked adrenaline-induced constriction of an isolated rabbit auricle, indicating its potential cardiovascular effects.