Drug Interactions between BuSpar and tofacitinib

You should avoid the use of alcohol while being treated with busPIRone. Alcohol can increase the nervous system side effects of busPIRone such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. Patients receiving busPIRone should preferably avoid the consumption of large amounts of grapefruits and grapefruit juice. If this is not possible, the busPIRone dose should be taken at least 2 hours before or 8 hours after grapefruit or grapefruit juice. Large amounts of grapefruit and grapefruit juice may cause increased levels of busPIRone in your body. This can lead to increased adverse effects such as drowsiness. Talk to your doctor or pharmacist if you have any questions or concerns.

Consumer information for this interaction is not currently available.

MONITOR: Grapefruit juice may increase the plasma concentrations of tofacitinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. The extent and clinical significance are unknown. Moreover, pharmacokinetic alterations associated with interactions involving grapefruit juice are often subject to a high degree of interpatient variability.

MANAGEMENT: Until more information is available, some authorities recommend avoiding consumption of grapefruit juice during tofacitinib therapy (Canada). Patients receiving tofacitinib therapy who ingest grapefruits or grapefruit juice should be monitored for adverse effects and undue fluctuations in plasma drug levels.