Prodilidine is an arylpyrrolidine derivative patented by Mead Johnson & Co.as moderately potent analgesic. By comparison with other drugs, including morphine, Prodilidine has a prompt and unusually sustained antinociceptive action in rodents by all routes. Prodilidine substantially lacks antipyretic, anti-inflammatory, antitussive, constipating, respiratory depressant, and cardiovascular effects. Prodilidine resembles meperidine in excitatory properties and body-temperature lowering action at high dosage. The d-isomer is about twice as potent and toxic as the l-isomer parenterally; by the gastric route, the difference is markedly less.