Prodilidine

Prodilidine (CI-427) is an orally active, pyrrolidine-derived non-narcotic pain inhibitor. Prodilidine exerts analgesic activity against various nociceptive stimuli, and shows no antipyretic, anti-inflammatory or respiratory depressive effects. Prodilidine fails to inhibit withdrawal symptoms of addictive agents in monkeys, but exhibits excitatory effects and enhances the crossed extensor reflex at toxic doses. Prodilidine is well absorbed from the gastrointestinal tract and metabolized via hepatic microsomal N-demethylation, displaying isomer-specific activity, toxicity and metabolic characteristics. Prodilidine can be used in research related to chronic pain (e.g., cancer-, musculoskeletal/arthritis-derived), traumatic pain and arthritic pain^[1][2][3]. In Vitro:Prodilidine undergoes N-demethylation via liver microsomes from multiple species, with the (-)-Prodilidine showing greater demethylation than the (+)-Prodilidine by rat liver microsomes^[1]. In Vivo:Prodilidine hydrochloride (7.2-84.0 mg/kg; p.o.; s.c.; i.v.) exhibits analgesic activity in mice, with ED₅₀ values ranging from 7.2 mg/kg (subcutaneous, writhing assay) to 84.0 mg/kg (oral, tail-pinch assay), and LD₅₀ values ranging from 91 mg/kg (intravenous) to 318 mg/kg (oral)^[1].
Prodilidine hydrochloride (11.2-17.8 mg/kg; p.o.; s.c.; i.v.) exhibits analgesic activity in rats, with ED₅₀ values ranging from 11.2 mg/kg (intravenous) to 17.3 mg/kg (oral) in the tail-flick assay, and LD₅₀ values ranging from 74 mg/kg (intravenous) to 253 mg/kg (oral)^[1].