erdafitinib (Rx)

Brand and Other Names:Balversa
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 3mg
  • 4mg
  • 5mg

Urothelial Carcinoma

Indicated for locally advanced or metastatic urothelial carcinoma that has fibroblast growth factor receptor-2 (FGFR2) or FGFR3 genetic alterations and progressed during or following at least 1 line of prior platinum-containing chemotherapy, including within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy

8 mg PO qDay initially; increase to 9 mg PO qDay based on serum phosphate (PO4) levels and tolerability at 14-21 days

Continue until disease progression or unacceptable toxicity

Increase dose to 9 mg qDay if serum phosphate level <5.5 mg/dL and there are no ocular disorders or Grade ≥2 adverse reactions

Dosage Modifications

Dose reduction schedule

  • 9 mg/day reduction schedule
    • First: 8 mg/day
    • Second: 6 mg/day
    • Third: 5 mg/day
    • Fourth: 4 mg/day
    • Fifth: Stop drug if fifth reduction needed
  • 8 mg/day reduction schedule
    • First: 6 mg/day
    • Second: 5 mg/day
    • Third: 4 mg/day
    • Fourth: Stop drug if fourth reduction needed

Hyperphosphatemia

  • In all patients, restrict phosphate intake to 600-800 mg/day; if serum phosphate >7 mg/dL, consider adding oral phosphate binder until serum phosphate level returns to <5.5 mg/dL
  • Phosphate levels and dosage
    • 5.6-6.9 mg/dL (1.8-2.3 mmol/L): Continue at current dose
    • 7-9 mg/dL (2.3-2.9 mmol/L): Withhold; reassess weekly until phosphate <5.5 mg/dL (or baseline), then resume at same dose level; implement dose reduction if hyperphosphatemia lasts >1 week
    • >9 mg/dL (>2.9 mmol/L): Withhold; reassess weekly until phosphate <5.5 mg/dL (or baseline), then restart at 1 dose level lower
    • >10 mg/dL (>3.2 mmol/L) or significantly altered baseline renal function or Grade 3 hypercalcemia: Withhold; reassess weekly until phosphate <5.5 mg/dL (or baseline), then restart at 2 dose levels lower

Central serous retinopathy or retinal pigment epithelial detachment (CSR/RPED)

  • Grade 1
    • Asymptomatic; clinical or diagnostic observations only
    • Withhold drug until resolution
    • If resolves within 4 weeks, resume at the next lower dose level; then, if no recurrence for a month, consider reescalation
    • If stable for 2 consecutive eye examinations, but not resolved, resume at the next lower dose level
  • Grade 2
    • Visual acuity 20/40 or better or ≤3 lines of decreased vision from baseline
    • Withhold until resolution
    • If resolves within 4 weeks, may resume at the next lower dose level
  • Grade 3
    • Visual acuity worse than 20/40 or >3 lines of decreased vision from baseline
    • Withhold until resolution
    • If resolves within 4 weeks, may resume 2 dose levels lower
    • If recurs, consider permanent discontinuation
  • Grade 4
    • Visual acuity 20/200 or worse in affected eye
    • Permanently discontinue

Other adverse reactions

  • Grade 3: Withhold drug until resolves to Grade 1 or baseline, then may resume dose 1 level lower
  • Grade 4: Permanently discontinue

Renal impairment

  • Mild or moderate (eGFR 30-89 mL/min/1.73 m2): No clinically meaningful trends in the pharmacokinetics observed
  • Severe or dialysis: Unknown

Hepatic impairment

  • Mild (TB ≤ULN and AST >ULN or TB >1 to 1.5x ULN and any AST): No clinically meaningful trends in the pharmacokinetics observed
  • Moderate or severe: Unknown

Dosing Considerations

Patient selection

  • Selection based on the presence of susceptible FGFR genetic alterations in tumor specimens as detected by an FDA-approved companion diagnostic
  • Information on FDA-approved tests for the detection of FGFR genetic alterations in urothelial cancer is available at: http://www.fda.gov/CompanionDiagnostics

Monitoring

  • Assess serum phosphate levels 14-21 days after initiating
  • Monitor phosphate levels monthly for hyperphosphatemia

Safety and efficacy not established

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Interactions

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              • afatinib

                erdafitinib will increase the level or effect of afatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • aliskiren

                erdafitinib will increase the level or effect of aliskiren by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • alpelisib

                alpelisib will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • amiodarone

                amiodarone will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of amiodarone by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • amobarbital

                amobarbital will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • apalutamide

                apalutamide will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • atazanavir

                atazanavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • atorvastatin

                erdafitinib will increase the level or effect of atorvastatin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • betrixaban

                erdafitinib will increase the level or effect of betrixaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • bosentan

                bosentan will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • brentuximab vedotin

                erdafitinib will increase the level or effect of brentuximab vedotin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • butabarbital

                butabarbital will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • butalbital

                butalbital will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • calcium acetate

                calcium acetate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • calcium carbonate

                calcium carbonate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • capecitabine

                capecitabine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • carbamazepine

                carbamazepine will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • carfilzomib

                erdafitinib will increase the level or effect of carfilzomib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • carvedilol

                erdafitinib will increase the level or effect of carvedilol by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ceritinib

                erdafitinib will increase the level or effect of ceritinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

                ceritinib will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • cetirizine

                erdafitinib will increase the level or effect of cetirizine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • chloramphenicol

                chloramphenicol will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2E1 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • cimetidine

                erdafitinib will increase the level or effect of cimetidine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • clarithromycin

                clarithromycin will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • cobicistat

                cobicistat will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • colchicine

                erdafitinib will increase the level or effect of colchicine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • conivaptan

                conivaptan will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • crizotinib

                erdafitinib will increase the level or effect of crizotinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • cyclosporine

                erdafitinib will increase the level or effect of cyclosporine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • dabigatran

                erdafitinib will increase the level or effect of dabigatran by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • dabrafenib

                dabrafenib will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • darunavir

                darunavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • daunorubicin

                erdafitinib will increase the level or effect of daunorubicin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • desloratadine

                erdafitinib will increase the level or effect of desloratadine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • dexamethasone

                erdafitinib will increase the level or effect of dexamethasone by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • digoxin

                erdafitinib will increase the level or effect of digoxin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • diltiazem

                erdafitinib will increase the level or effect of diltiazem by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • docetaxel

                erdafitinib will increase the level or effect of docetaxel by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • doxorubicin

                erdafitinib will increase the level or effect of doxorubicin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • edoxaban

                erdafitinib will increase the level or effect of edoxaban by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • efavirenz

                efavirenz will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

                efavirenz will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • enzalutamide

                enzalutamide will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • erythromycin base

                erdafitinib will increase the level or effect of erythromycin base by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • erythromycin ethylsuccinate

                erdafitinib will increase the level or effect of erythromycin ethylsuccinate by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • erythromycin lactobionate

                erdafitinib will increase the level or effect of erythromycin lactobionate by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • erythromycin stearate

                erdafitinib will increase the level or effect of erythromycin stearate by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • estradiol

                erdafitinib will increase the level or effect of estradiol by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • etoposide

                erdafitinib will increase the level or effect of etoposide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • etravirine

                etravirine will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

                etravirine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Reduce dose of osilodrostat, a CYP3A4 substrate, by half when coadministered with a strong CYP3A4 inhibitor.

              • everolimus

                erdafitinib will increase the level or effect of everolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ferric citrate

                ferric citrate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • fexofenadine

                erdafitinib will increase the level or effect of fexofenadine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • fluconazole

                fluconazole will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • fluorouracil

                fluorouracil will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • fluorouracil topical

                fluorouracil topical will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • flurbiprofen

                flurbiprofen will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • fluvastatin

                fluvastatin will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • fosamprenavir

                erdafitinib will increase the level or effect of fosamprenavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • fosphenytoin

                fosphenytoin will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • gemfibrozil

                gemfibrozil will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • gilteritinib

                erdafitinib will increase the level or effect of gilteritinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • grapefruit

                grapefruit will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • hydrocortisone

                erdafitinib will increase the level or effect of hydrocortisone by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ibuprofen

                ibuprofen will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • idarubicin

                erdafitinib will increase the level or effect of idarubicin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • idelalisib

                idelalisib will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • imatinib

                erdafitinib will increase the level or effect of imatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • indinavir

                indinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of indinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • indomethacin

                indomethacin will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • irbesartan

                irbesartan will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • irinotecan

                erdafitinib will increase the level or effect of irinotecan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • irinotecan liposomal

                erdafitinib will increase the level or effect of irinotecan liposomal by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • isoniazid

                isoniazid will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • itraconazole

                itraconazole will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • ivermectin

                erdafitinib will increase the level or effect of ivermectin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ivosidenib

                ivosidenib will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • ketoconazole

                ketoconazole will increase the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4/CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4/CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • lanthanum carbonate

                lanthanum carbonate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • lapatinib

                erdafitinib will increase the level or effect of lapatinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • larotrectinib

                erdafitinib will increase the level or effect of larotrectinib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ledipasvir/sofosbuvir

                erdafitinib will increase the level or effect of ledipasvir/sofosbuvir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • loperamide

                erdafitinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • lopinavir

                lopinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • loratadine

                erdafitinib will increase the level or effect of loratadine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • lorlatinib

                lorlatinib will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • losartan

                losartan will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • lovastatin

                erdafitinib will increase the level or effect of lovastatin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • lumacaftor/ivacaftor

                lumacaftor/ivacaftor will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • mefenamic acid

                mefenamic acid will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • methotrexate

                erdafitinib will increase the level or effect of methotrexate by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • miconazole oral

                miconazole oral will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • midazolam

                erdafitinib, midazolam. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

              • mifepristone

                mifepristone will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • mitomycin

                erdafitinib will increase the level or effect of mitomycin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • mitotane

                mitotane will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • morphine

                erdafitinib will increase the level or effect of morphine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nadolol

                erdafitinib will increase the level or effect of nadolol by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nafcillin

                nafcillin will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • naldemedine

                erdafitinib will increase the level or effect of naldemedine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nefazodone

                nefazodone will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • nelfinavir

                nelfinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of nelfinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nicardipine

                nicardipine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of nicardipine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nintedanib

                erdafitinib will increase the level or effect of nintedanib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • nitisinone

                nitisinone will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • olanzapine

                olanzapine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • omeprazole

                omeprazole will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • ondansetron

                erdafitinib will increase the level or effect of ondansetron by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • paclitaxel

                erdafitinib will increase the level or effect of paclitaxel by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • paclitaxel protein bound

                erdafitinib will increase the level or effect of paclitaxel protein bound by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • paliperidone

                erdafitinib will increase the level or effect of paliperidone by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • pazopanib

                erdafitinib will increase the level or effect of pazopanib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • pentobarbital

                pentobarbital will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • phenobarbital

                phenobarbital will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • phenytoin

                phenytoin will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • pimozide

                erdafitinib, pimozide. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

              • piroxicam

                piroxicam will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • posaconazole

                posaconazole will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • potassium acid phosphate

                potassium acid phosphate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • potassium phosphate

                potassium phosphate, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • primidone

                primidone will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • pyrimethamine

                pyrimethamine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • quinidine

                erdafitinib, quinidine. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

                erdafitinib, quinidine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

                erdafitinib will increase the level or effect of quinidine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • quinine

                erdafitinib, quinine. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

                erdafitinib, quinine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

                erdafitinib will increase the level or effect of quinine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

                quinine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • ranolazine

                erdafitinib will increase the level or effect of ranolazine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ribociclib

                ribociclib will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • rifabutin

                rifabutin will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • rifampin

                rifampin will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

                erdafitinib will increase the level or effect of rifampin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • rifapentine

                rifapentine will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • rimegepant

                erdafitinib will increase the level or effect of rimegepant by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

              • riociguat

                erdafitinib will increase the level or effect of riociguat by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • risperidone

                erdafitinib will increase the level or effect of risperidone by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • ritonavir

                ritonavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of ritonavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • romidepsin

                erdafitinib will increase the level or effect of romidepsin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • saquinavir

                saquinavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

                erdafitinib will increase the level or effect of saquinavir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • saxagliptin

                erdafitinib will increase the level or effect of saxagliptin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • secobarbital

                secobarbital will decrease the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. Avoid coadministration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

              • sevelamer

                sevelamer, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • silodosin

                erdafitinib will increase the level or effect of silodosin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • sirolimus

                erdafitinib, sirolimus. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

                erdafitinib will increase the level or effect of sirolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • sitagliptin

                erdafitinib will increase the level or effect of sitagliptin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • sodium phosphates, IV

                sodium phosphates, IV, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • sofosbuvir

                erdafitinib will increase the level or effect of sofosbuvir by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • sorafenib

                sorafenib will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • St John's Wort

                St John's Wort will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

              • stiripentol

                stiripentol will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • sucroferric oxyhydroxide

                sucroferric oxyhydroxide, erdafitinib. Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • sulfadiazine

                sulfadiazine will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • sulfamethoxazole

                sulfamethoxazole will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • tacrolimus

                erdafitinib, tacrolimus. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

                erdafitinib will increase the level or effect of tacrolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • temsirolimus

                erdafitinib will increase the level or effect of temsirolimus by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • teniposide

                erdafitinib will increase the level or effect of teniposide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • tipranavir

                tipranavir will increase the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • tolbutamide

                tolbutamide will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • tolvaptan

                erdafitinib will increase the level or effect of tolvaptan by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • trabectedin

                erdafitinib will increase the level or effect of trabectedin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • triazolam

                erdafitinib, triazolam. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with erdafitinib and sensitive CYP3A4 substrates with narrow therapeutic indices. Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate.

              • trimethoprim

                trimethoprim will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • vemurafenib

                erdafitinib will increase the level or effect of vemurafenib by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • venetoclax

                erdafitinib will increase the level or effect of venetoclax by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • verapamil

                erdafitinib will increase the level or effect of verapamil by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • vinblastine

                erdafitinib will increase the level or effect of vinblastine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • vincristine

                erdafitinib will increase the level or effect of vincristine by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • vincristine liposomal

                erdafitinib will increase the level or effect of vincristine liposomal by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • voriconazole

                voriconazole will increase the level or effect of erdafitinib by altering metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration with strong CYP3A4/CYP2C9 inhibitors, monitor closely for adverse reactions and consider decreasing dose accordingly. If strong CYP3A4/CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • warfarin

                warfarin will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              • zafirlukast

                zafirlukast will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

              Monitor Closely (29)

              • amantadine

                erdafitinib increases levels of amantadine by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • amiloride

                erdafitinib increases levels of amiloride by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • armodafinil

                armodafinil will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • berotralstat

                erdafitinib increases levels of berotralstat by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Reduced berotralstat dose to 110 mg/day when coadministered with P-gp inhibitors.

              • bexarotene

                bexarotene will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • brigatinib

                brigatinib will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • cimetidine

                erdafitinib increases levels of cimetidine by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • cisplatin

                erdafitinib increases levels of cisplatin by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • clobazam

                clobazam will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • dofetilide

                erdafitinib increases levels of dofetilide by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • dopamine

                dopamine increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • elvitegravir

                elvitegravir will decrease the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP2C9 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP2C9 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • enzalutamide

                enzalutamide will decrease the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP2C9 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP2C9 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • eslicarbazepine acetate

                eslicarbazepine acetate will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • famotidine

                famotidine increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • lamivudine

                lamivudine increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • memantine

                memantine increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • metformin

                metformin increases levels of erdafitinib by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • modafinil

                modafinil will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • oxaliplatin

                erdafitinib increases levels of oxaliplatin by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • pimozide

                erdafitinib, pimozide. Other (see comment). Modify Therapy/Monitor Closely. Comment: Avoid coadministration during initial dosing adjustment period (ie, first 21 days). Increases in serum phosphate levels are a pharmacodynamic effect of FGFR inhibition. Serum phosphate binders may obscure decisions regarding initial dosage increase.

              • pindolol

                erdafitinib increases levels of pindolol by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • pramipexole

                erdafitinib increases levels of pramipexole by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • procainamide

                erdafitinib increases levels of procainamide by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • rucaparib

                rucaparib will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP2C9 substrates, if clinically indicated.

              • siponimod

                siponimod and erdafitinib both increase immunosuppressive effects; risk of infection. Use Caution/Monitor. Caution if coadministered because of additive immunosuppressive effects during such therapy and in the weeks following administration. When switching from drugs with prolonged immune effects, consider the half-life and mode of action of these drugs to avoid unintended additive immunosuppressive effects.

              • telotristat ethyl

                telotristat ethyl will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

              • trimethoprim

                erdafitinib increases levels of trimethoprim by decreasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              • varenicline

                erdafitinib increases levels of varenicline by increasing renal clearance. Modify Therapy/Monitor Closely. Consider alternatives that are not OCT2 substrates or consider reducing the dose of OCT2 substrates based on tolerability.

              Minor (1)

              • encorafenib

                encorafenib will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. If a moderate CYP3A4 inducer must be coadministered, administer 8-mg/day dose initially, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability. If a moderate CYP3A4 inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg. When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity.

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              Adverse Effects

              >10% (All Grades)

              Phosphate increased (76%)

              Stomatitis (56%)

              Fatigue (54%)

              Creatinine increased (52%)

              Diarrhea (47%)

              Dry mouth (45%)

              ALT increased (41%)

              Alkaline phosphatase increased (41%)

              Onycholysis (41%)

              Sodium decreased (40%)

              Decreased appetite (38%)

              Albumin decreased (37%)

              Dysgeusia (37%)

              Hemoglobin decreased (35%)

              Dry skin (34%)

              AST increased (30%)

              Magnesium decreased (30%)

              Constipation (28%)

              Dry eye (28%)

              Palmar-plantar erythrodysesthesia (26%)

              Alopecia (26%)

              Phosphate decreased (24%)

              Abdominal pain (23%)

              Calcium increased (22%)

              Nausea (21%)

              Musculoskeletal pain (20%)

              Platelets decreased (19%)

              Leukocytes decreased (17%)

              Blurred vision (17%)

              Paronychia (17%)

              Urinary tract infection (17%)

              Potassium increased (16%)

              Weight decreased (16%)

              Pyrexia (14%)

              Vomiting (13%)

              Nail discoloration (11%)

              Conjunctivitis (11%)

              Oropharyngeal pain (11%)

              Hematuria (11%)

              Arthralgia (11%)

              >10% (Grades 3-4)

              Sodium decreased (16%)

              1-10% (All Grades)

              Neutrophils decreased (10%)

              Fasting glucose increased (10%)

              Lacrimation increased (10%)

              Dyspnea (10%)

              1-10% (Grades 3-4)

              Fatigue (10%)

              Onycholysis (10%)

              Phosphate decreased (9%)

              Stomatitis (9%)

              Palmar-plantar erythrodysesthesia (6%)

              Urinary tract infection (6%)

              Dry eye (6%)

              Creatinine increased (5%)

              Hemoglobin decreased (3%)

              Calcium increased (3%)

              Paronychia (3%)

              Neutrophils decreased (2%)

              Diarrhea (2%)

              Abdominal pain (2%)

              Vomiting (2%)

              Dyspnea (2%)

              Hematuria (2%)

              Platelets decreased (1%)

              Phosphate increased (1%)

              ALT increased (1%)

              Alkaline phosphatase increased (1%)

              Magnesium decreased (1%)

              Constipation (1%)

              Nausea (1%)

              Pyrexia (1%)

              Dysgeusia (1%)

              Oropharyngeal pain (1%)

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              Warnings

              Contraindications

              None

              Cautions

              Based on mechanism of action and animal studies, can cause fetal harm if administered to pregnant women

              Ocular disorders

              • Can cause ocular disorders, including central serous retinopathy/retinal pigment epithelial detachment (CSR/RPED), resulting in visual-field defect
              • Perform monthly ophthalmological examinations during first 4 months of treatment and then every 3 months afterwards, and urgently at any time for visual symptoms
              • Dry eye symptoms are common; all patients should receive dry eye prophylaxis with ocular demulcents as needed

              Hyperphosphatemia

              • Increases in serum phosphate levels are a pharmacodynamic effect as a consequence of FGFR inhibition
              • Median onset time for any grade event of hyperphosphatemia was 20 days
              • Monitor for hyperphosphatemia and follow dose modifications when required
              • Patients may require phosphate binders during treatment

              Drug interaction overview

              • Moderate CYP2C9 or strong CYP3A4 inhibitors
                • Coadministration increases erdafitinib plasma concentrations
                • Consider alternant therapiesIf coadministration is unavoidable, monitor closely for adverse reactions and consider dose modifications accordingly
                • If the moderate CYP2C9 or strong CYP3A4 inhibitor is discontinued, erdafitinib dose may be increased
              • Strong CYP2C9 or CYP3A4 inducers
                • Coadministration may significantly decrease erdafitinib plasma concentrations and efficacy
                • Avoid coadministration
              • Moderate CYP2C9 or CYP3A4 inducers
                • Coadministration may significantly decrease erdafitinib plasma concentrations and efficacyIf moderate inducer must be coadministered at start of treatment, start at 8-mg/day dose, with potential to increase to 9 mg/day based on serum phosphate levels on Days 14-21 and tolerability
                • If moderate inducer must be coadministered after the initial dose increase period based on serum phosphate levels and tolerability, increase erdafitinib dose up to 9 mg
                • When a moderate inducer discontinued, continue erdafitinib at same dose, in absence of drug-related toxicity
              • Serum phosphate level-altering drugs
                • Coadministration with other serum phosphate level-altering agents may increase or decrease serum phosphate levels
                • Avoid coadministration before initial dose increase period (Days 14-21)
              • CYP3A4 substrates
                • Erdafitinib may altered plasma concentrations of CYP3A4 substrates, leading to either loss of activity or increased toxicity of the substrate
                • Avoid coadministration with sensitive CYP3A4 substrates with narrow therapeutic indices
              • OCT2 substrates
                • Erdafitinib may increase plasma concentrations of OCT2 substrates
                • Consider alternant therapies
              • P-gp substrates
                • Erdafitinib may increase plasma concentrations of P-gp substrates
                • If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index
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              Pregnancy

              Pregnancy

              Based on the mechanism of action and findings in animal reproduction studies, can cause fetal harm when administered to pregnant women

              Animal studies: Administration to pregnant rats during organogenesis caused malformations and embryofetal death at maternal exposures that were less than the human exposures at the maximum recommended human dose based on AUC

              Pregnancy testing recommended for females of reproductive potential before initiating erdafitinib

              Infertility: Based on findings in animal studies, may impair fertility in females of reproductive potential

              Contraception

              • Females: Advise females of reproductive potential to use effective contraception during treatment and for 1 month after last dose
              • Males: Advise male patients with female partners of reproductive potential to use effective contraception during treatment and for 1 month after last dose

              Lactation

              No data are available on presence in human milk, effects on breastfed children, or on milk production

              Owing to potential serious adverse reactions in breastfed children, advise lactating women not to breastfeed during treatment and for 1 month following last dose

              Pregnancy Categories

              A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

              B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

              C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

              D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

              X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

              NA: Information not available.

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              Pharmacology

              Mechanism of Action

              Fibroblast growth factor receptor (FGFR) inhibitor; FGFRs are a family of receptor tyrosine kinases

              In vitro, erdafitinib inhibits FGFR phosphorylation and signaling and decreases cell viability in cell lines expressing FGFR genetic alterations, including point mutations, amplifications, and fusions

              Absorption

              Peak plasma time: 2.5 hr

              Peak plasma concentration: 1399 ng/mL

              AUC: 29,268 ng·hr/mL

              Distribution

              Vd: 29 L

              Protein bound: 99.8%; primarily to alpha-1-acid glycoprotein

              Metabolism

              Primarily metabolized by CYP2C9 and CYP3A4

              Contribution of CYP2C9 and CYP3A4 in total clearance of erdafitinib is estimated to be 39% and 20%, respectively

              Unchanged erdafitinib was the major drug-related moiety in plasma; there were no circulating metabolites

              Elimination

              Half-life: 59 hr

              Total clearance: 0.362 L/hr

              Excretion: 69% feces (19% unchanged); 19% urine (19% unchanged)

              Pharmacogenomics

              CYP2C9 poor metabolizers

              • CYP2C9*3/*3 genotype: Erdafitinib systemic exposure predicted to be 50% higher
              • Estimated to be present in 0.4-3% of the population among various ethnic groups
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              Administration

              Oral Administration

              May take with or without food

              Swallow tablets whole; do not chew or crush

              Vomited dose: If vomiting occur any time after taking erdafitinib, the next dose should be taken the next day

              Missed dose

              • Take missed dose as soon as possible on the same day
              • Resume regular daily dose schedule the next day
              • Extra tablets should not be taken to make up for the missed dose

              Storage

              Store at 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86ºF)

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              Images

              No images available for this drug.
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              Patient Handout

              A Patient Handout is not currently available for this monograph.
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              Formulary

              FormularyPatient Discounts

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              To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

              Adding plans allows you to:

              • View the formulary and any restrictions for each plan.
              • Manage and view all your plans together – even plans in different states.
              • Compare formulary status to other drugs in the same class.
              • Access your plan list on any device – mobile or desktop.

              The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

              Tier Description
              1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
              2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
              3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
              4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
              NC NOT COVERED – Drugs that are not covered by the plan.
              Code Definition
              PA Prior Authorization
              Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
              QL Quantity Limits
              Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
              ST Step Therapy
              Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
              OR Other Restrictions
              Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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              Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.