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4-Fluoropethidine is a drug that is a derivative of pethidine (meperidine), which combines pethidine's opioidanalgesic effects with increased monoaminereuptake inhibition. It is around 50% less potent than pethidine as an opioid analgesic, but conversely is 50% more potent as a dopamine reuptake inhibitor, with other derivatives such as the 4-iodo and 3,4-dichloro analogues being even more potent dopamine reuptake inhibitors again. However none of these compounds substitute for cocaine or produce stimulant effects in animals, suggesting that they still act primarily as opioid analgesic drugs in practice.