Table 5

Inhibition of terfenadine metabolism (CYP3A4) by coadministration of ketoconazole

Dose (mg)RouteCmax (ng/ml)CLtot(ml/min)
control  60p.o.<784300
+ ketoconazole81
CLr(ml/min)CLh (ml/min)CLh,m(ml/min)CLh,m/CLtot Iin,u/Ki
negligible84300110005-a, 379005-b 0.135-a, 0.455-b 3.3–3.85-a
0.33–0.385-b

  • ↵5-a the values for N-dealkylation.

  • ↵5-b the values for hydroxylation.