Table 2

Potential drug interactions resulting from cassette dosing

ProcessProtein InvolvedSaturable?Direct Consequence of Competitive Inhibition
Gut lumenal hydrolysis
 EnzymaticHydrolasesYesIncreased F
Gut wall uptake
 ActiveTransportersYesDecreased F
Gut wall effluxPGPYesIncreased F
Gut wall metabolismP450, UGT, etc.YesIncreased F
Hepatic uptakeTransportersYesDecreased CL/Increased F
Hepatic metabolismP450, UGT, etc.YesDecreased CL/Increased F
Biliary effluxTransportersYesDecreased CL/Increased F
Plasma protein bindingAlbumin, AGPYesIncreased CL of low clearance drugs
Renal glomerular filtrationNoneNoNone
Renal metabolismP450, UGT, etc.YesDecreased CL
Renal tubular secretion
 ActiveTransportersYesDecreased CL
Renal tubular reuptake
 ActiveTransportersYesIncreased CL
  • P450, cytochrome P450; PGP, P-glycoprotein; UGT, UDP-glucuronyl transferase; AGP, α1-acid glycoprotein.