The and are the independent PK parameters (i.e. they do not affect each other). However, both the and Vd determine the and the of the drug.
Cefadroxil
CLT = 0.18 L/hr/kg
Vd = 0.24 L/kg
Cefamandole
CLT = 0.18 L/hr/kg
Vd = 0.16 L/kg
Cefadroxil:
k = CLT/Vd = 0.75 hr-1
Cefamandole:
k = CLT/Vd = 1.125 hr-1
Cefadroxil and cefamandole have similar total body clearance, however cefadroxil has larger Vd. The larger Vd makes cefadroxil plasma conc. disappears at a rate slower than that of cefamandole (smaller k and longer half life).
