Meperidine pharmacokinetics

Pharmacokinetics Unlike morphine, meperidine is well absorbed from the gastrointestinal tract and is useful when an orally-administered, potent analgesic is needed. However, meperidine is most often administered intramuscularly. The drug has a duration of action of 2 to 4 hours, which is shorter than that of morphine (see Figure 14.6). Meperidine is N-demethylated in the liver and is excreted in the urine. [Note Because of its shorter action and dif-... 

The pharmacokinetics and effects of various systemically administered analgesics on the uterus, fetus, and neonate have been reviewed (SED-11, 137). Fetal bradycardia lasting up to 7 minutes was reported in 53 of 1910 fetuses (2.7%) after the administration of pethidine (meperidine) 75 mg and promethazine 25 mg intravenously to the mothers during labor (SED-11,137) (95). 

Piscitelli SC, Kress DR, BertzRJ, Pau A, Davey R. The effect ofritonavir on the pharmacokinetics of meperidine and normeperidine. Pharmacotherapy (2000) 20, 549-53. 

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