Table 1.
Site and effect of drug interactions with fexofenadine
| Drug | Interaction | Effect of interaction on fexofenadine peak concentration |
|---|---|---|
| Ketoconazole | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Itraconazole | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Verapamil | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Erythromycin | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Ritonavir | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Lopinavir/ritonavir | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| St John’s Wort | Inhibit P-glycoprotein | Decrease intestinal absorption and increased fexofenadine peak concentration |
| Omeprazole | Interacts at P-glycoprotein | None |
| Indomethacin | Inhibit multidrug resistant-associated protein | None |
| Probenecid | Inhibit multidrug resistant-associated protein | Decreased renal clearance and no change in peak concentration |
| Rifamycin | Inhibit organic anion-transporting polypeptide | None |
| Rifampin | Induction of P-glycoprotein | Increased fexofenadine clearance |