P-glycoprotein Inducers:
Comment:
Rifampin and St. John's wort have been shown to substantially reduce the plasma concentration of digoxin; although data are limited, other P-glycoprotein inducers may have a similar effect on digoxin concentrations. Although some evidence suggests that carbamazepine induces P-gp, one study found no effect of carbamazepine on digoxin serum concentrations. Several days to weeks may be required to see the full effect a P-glycoprotein inducer on digoxin.
Class 3: Assess Risk & Take Action if Necessary