Drug Interaction Report

Theoretically, agents that are thought to have immunostimulant properties such as echinacea, vitamin E, cat's claw, and zinc may antagonize the pharmacologic effects of immunosuppressants. However, clinical cases of drug interactions have not been reported.

MONITOR: Additive effects and possible toxicity (e.g., hypercalcemia, hypercalciuria, and/or hyperphosphatemia) may occur when patients using vitamin D and/or vitamin D analogs ingest a diet high in vitamin D, calcium, and/or phosphorus. The biologically active forms of vitamin D stimulate intestinal absorption of calcium and phosphorus. This may be helpful in patients with hypocalcemia and/or hypophosphatemia. However, sudden increases in calcium or phosphorus consumption due to dietary changes could precipitate hypercalcemia and/or hyperphosphatemia. Patients with certain disease states, such as impaired renal function, may be more susceptible to toxic side effects like ectopic calcification. On the other hand, if dietary calcium is inadequate for the body's needs, the active form of vitamin D will stimulate osteoclasts to pull calcium from the bones. This may be detrimental in a patient with reduced bone density.

MANAGEMENT: Given the narrow therapeutic index of vitamin D and vitamin D analogs, the amounts of calcium, phosphorus, and vitamin D present in the patient's diet may need to be taken into consideration. Specific dietary guidance should be discussed with the patient and regular lab work should be monitored as indicated. Calcium, phosphorus, and vitamin D levels should be kept within the desired ranges, which may differ depending on the patient's condition. Patients should also be counseled on the signs and symptoms of hypervitaminosis D, hypercalcemia, and/or hyperphosphatemia.

MONITOR: Smoking during treatment with deuruxolitinib may increase the risk of major adverse cardiovascular events (MACE) and the risk of developing malignancies. In clinical studies of deuruxolitinib, individuals who were current or former smokers had an additional increased risk of overall malignancies. Also, deuruxolitinib may increase patients' risk of MACE, including myocardial infarction, stroke, and cardiovascular death.

MANAGEMENT: Caution is advised if deuruxolitinib is prescribed to current or past smokers. Patients should be informed about the symptoms of serious cardiovascular events and the steps to take if they occur. The manufacturer recommends discontinuing deuruxolitinib in patients that have experienced a myocardial infarction or stroke. Deuruxolitinib may be taken with or without food.