Efient* 5 mg film-coated tablets. Efient 10mg film-coated t(九)
intervention.
Absorption
The absorption and metabolism of prasugrel are rapid, with peak plasma concentration (Cmax) of the active metabolite occurring in approximately 30 minutes. The active metabolite's exposure (AUC) increases proportionally over the therapeutic dose range. In a study of healthy subjects, AUC of the active metabolite was unaffected by a high fat, high calorie meal, but Cmax was decreased by 49% and the time to reach Cmax (Tmax) was increased from 0.5 to 1.5 hours. Efient was administered without regard to food in TRITON. Therefore, Efient can be administered without regard to food; however, the administration of prasugrel loading dose in the fasted state may provide most rapid onset of action (see section 4.2).
Distribution
Active metabolite binding to human serum albumin (4% buffered solution) was 98%.
Metabolism
Prasugrel is not detected in plasma following oral administration. It is rapidly hydrolysed in the intestine to a thiolactone, which is then converted to the active metabolite by a single step of cytochrome P450 metabolism, primarily by CYP3A4 and CYP2B6, and to a lesser extent by CYP2C9 and CYP2C19. The active metabolite is further metabolised to two inactive compounds by S-methylation, or conjugation with cysteine.
In healthy subjects, patients with stable atherosclerosis, and patients with ACS receiving Efient, there was no relevant effect of genetic variation in CYP3A5, CYP2B6, CYP2C9, or CYP2C19 on the pharmacokinetics of prasugrel or its inhibition of platelet aggregation.
Elimination
Approximately 68% of the prasugrel dose is excreted in the urine and 27% in the faeces, as inactive metabolites. The active metabolite has an elimination half-life of about 7.4 hours (range 2 to 15 hours).
Special Populations
Elderly: In a study of healthy subjects between the ages of 20 and 80 years, age had no significant effect on pharmacokinetics of prasugrel or its inhibition of platelet aggregation. In the large phase 3 clinical trial, the mean estimated exposure (AUC) of the active metabolite was 19% higher in very elderly patients (75 years of age) compared to subjects <75 years of age. Prasugrel should be used with caution in patients 75 years of age due to the potential risk of bleeding in this population (see sections 4.2 and 4.4).
Hepatic impairment: No dose adjustment is necessary for patients with mild to moderate impaired hepatic function (Child-Pugh class A and B). Pharmacokinetics of prasugrel and its inhibition of platelet aggregation were similar in subjects with mild to moderate hepatic impairment compared to healthy subjects. Pharmacokinetics and pharmacodynamics of prasugrel in patients with severe hepatic impairment have not been studied. Prasugrel must not be used in patients with severe hepatic impairment (see section 4.3).
Renal impairment: No dosage adjustment is necessary for patients with renal impairment, including patients with end stage renal disease (ESRD). Pharmacokinetics of prasugrel and its inhibition of platelet aggregation are similar in patients with moderate renal impairment (GFR 30-<50 ml/min/1.73m2) and healthy subjects. Prasugrel-mediated inhibition of platelet aggregation was also similar in patients with ESRD who required haemodialysis compared to healthy subjects, although Cmax and AUC of the active metabolite decreased 51% and 42%, respectively, in ESRD patients.
Body weight: The mean exposure (AUC) of the active metabolite of prasugrel is approximately 30 |
