Introduction - Tramadol is a centrally acting analgesic drug largely metabolized in animal species. Its clinical response is mainly due to the MI metabolite, poorly produced in dogs. Grapefruit-juice can affect the pharmacokinetics of different drugs in animals and human beings. Aim - To evaluate the pharmacokinetics of tramadol and its major metabolites after both single oral administration of tramadol and co-administration of tramadol and frozen-dried grapefruit-juice. Material and methods - A balanced cross-over study was used, involving six male Beagle dogs. They were administered with tramadol alone (5 mg/kg) and with tramadol (5 mg/kg) plus frozen-dried grapefruit-juice (10 g). Results - The tramadol plasma concentration vs time curves showed significant differences during the first 4 hours following drug administration. Cmax was reached at 1.33 and 1.70 hours following tramadol and tramadol plus frozen-dried grapefruit-juice treatment, respectively. M I reached its Cmax at 1.36 and 0.86 hours following the above mentioned treatments, respectively. M2 and M5 do not show significant differences after both administrations. Discussion - Frozen-dried grapefruit-juice has shown to affect the plasma concentrations of MI despite them were well below to those reported in the human.
Effect of frozen-dried grapefruit-juice on the oral administration of tramadol in Beagle dogs
SACCOMANNI, GIUSEPPE;Giorgi M.
2011-01-01
Abstract
Introduction - Tramadol is a centrally acting analgesic drug largely metabolized in animal species. Its clinical response is mainly due to the MI metabolite, poorly produced in dogs. Grapefruit-juice can affect the pharmacokinetics of different drugs in animals and human beings. Aim - To evaluate the pharmacokinetics of tramadol and its major metabolites after both single oral administration of tramadol and co-administration of tramadol and frozen-dried grapefruit-juice. Material and methods - A balanced cross-over study was used, involving six male Beagle dogs. They were administered with tramadol alone (5 mg/kg) and with tramadol (5 mg/kg) plus frozen-dried grapefruit-juice (10 g). Results - The tramadol plasma concentration vs time curves showed significant differences during the first 4 hours following drug administration. Cmax was reached at 1.33 and 1.70 hours following tramadol and tramadol plus frozen-dried grapefruit-juice treatment, respectively. M I reached its Cmax at 1.36 and 0.86 hours following the above mentioned treatments, respectively. M2 and M5 do not show significant differences after both administrations. Discussion - Frozen-dried grapefruit-juice has shown to affect the plasma concentrations of MI despite them were well below to those reported in the human.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
