Drug Interactions between erdafitinib and Hyolev MB

MONITOR CLOSELY: The following interaction applies only to products containing sodium biphosphate that are used for bowel cleansing. It does not apply to products containing sodium biphosphate that are used for other, non-laxative related purposes.

Coadministration with agents that affect renal function or perfusion such as diuretics, ACE inhibitors, angiotensin receptor blockers, and nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of acute phosphate nephropathy associated with the use of bowel-cleansing phosphate solutions. The risk and/or severity of fluid and electrolyte disturbances may also be increased, which can lead to serious adverse events including cardiac arrhythmias, seizures, and renal impairment. Acute phosphate nephropathy is a rare adverse event that presents as acute renal failure with minimal proteinuria and a bland urine sediment. Renal biopsy findings are consistent with nephrocalcinosis and include acute and/or chronic renal tubular injury, calcium-phosphate crystal deposition in the distal tubules and collecting ducts, and no other pattern of histological injury. The risk of acute phosphate nephropathy stems from the large phosphate load, fluid shifts, and decreased intravascular volume, which can be exacerbated in the presence of medications that affect renal perfusion or function. In reported cases, acute renal failure was typically diagnosed within two to five months of colonoscopy. These cases often resulted in permanent impairment of renal function, some requiring long-term dialysis.

MANAGEMENT: Caution is advised when bowel-cleansing phosphate preparations are prescribed in patients treated with agents that affect renal function or perfusion, particularly if they are frail or elderly. Bowel-cleansing phosphate preparations should not be used in patients who have impaired renal function or perfusion, dehydration, or uncorrected electrolyte abnormalities. In patients at risk for acute phosphate nephropathy, baseline and postprocedure labs including serum electrolytes, calcium, phosphate, BUN, and creatinine should be performed. Patients should be advised not to exceed the recommended dosage of their bowel-cleansing preparation and to drink sufficient quantities of clear fluids during before, during, and after bowel cleansing. Limited data suggest that administration of an electrolyte rehydration solution may attenuate the electrolyte abnormalities and hypovolemia. Hospitalization and intravenous fluid hydration may be appropriate for frail or elderly patients who may be unable to drink an adequate volume of fluid.

Switch to consumer interaction data

MONITOR CLOSELY: Coadministration with agents that can alter serum phosphate levels may affect the initial dosage determination of erdafitinib. The mechanism appears to be related to the pharmacodynamic effects of fibroblast growth factor receptor (FGFR) inhibition, which has been shown to lead to an increase in serum phosphate levels, including hyperphosphatemia. Hyperphosphatemia can cause precipitation of calcium-phosphate crystals which over time can lead to hypocalcemia, soft tissue mineralization such as cutaneous calcification and calcinosis, secondary hyperparathyroidism, anemia, muscle cramps, seizures, QT prolongation, and arrhythmias. Soft tissue mineralization, including cutaneous calcification, calcinosis, and non-uremic calciphylaxis have been observed during treatment with other FGFR inhibitors. In clinical trials with erdafitinib, hyperphosphatemia (all grades) was reported as an adverse event in 76% of erdafitinib-treated patients, with a median onset time of 20 days, requiring phosphate binder therapy in 32% of patients. During these clinical trials, agents known to increase serum phosphate levels (e.g., potassium phosphate supplements, vitamin D supplements, some antacids, phosphate-containing enemas or laxatives, and medications known to have phosphate as an excipient) were prohibited with erdafitinib therapy unless no alternative was available; however, phosphate binders were permitted to treat increases in serum phosphate levels.

MANAGEMENT: The manufacturer of erdafitinib advises avoiding concomitant use with agents that may alter serum phosphate levels before its initial dose increase period, which is between 14 to 21 days of starting erdafitinib therapy and is based on serum phosphate levels. This includes agents that may decrease serum phosphate levels, such as phosphate binders, or increase serum phosphate levels, such as potassium phosphate supplements, vitamin D supplements, antacids, phosphate-containing enemas or laxatives, and medications known to have phosphate as an excipient. In addition, close monitoring of serum phosphate levels is recommended throughout treatment with erdafitinib, particularly if used concomitantly with agents that may increase serum phosphate levels. In the event of hyperphosphatemia, dose adjustment of erdafitinib, use of phosphate-lowering therapy, dietary phosphate restriction, and/or temporary or permanent treatment cessation of erdafitinib may be required according to the duration and severity of the hyperphosphatemia. The manufacturer's product labeling should be consulted for further information and dosage adjustment guidance.

Switch to consumer interaction data