| Absorption |
| Interacting medications (eg, cholestyramine) |
| Motility agents |
| Diarrhea or constipation |
| Presence or absence of food |
| Brand versus generic, formulation |
| Distribution |
| Hematocrit |
| Metabolism |
| Interacting prescription medications |
| Interacting over-the-counter medications |
| Interacting herbal supplements |
| Interacting beverages (eg, grapefruit juice) |
| Genetic polymorphism in CYP3A5 |
| Hepatic impairment |
| Other |
| Timing of concentration |
| Type of laboratory immunoassay |
| Schedule and frequency |
| Adherence |
