fedratinib

Absorption: Well absorbed following oral administration.

Distribution: Extensively distributed to tissues.

Protein Binding: ≥92%.

Metabolism/Excretion: Mostly metabolized in the liver via the CYP3A4 and CYP2C19 isoenzymes. Primarily excreted in feces (77%, 23% as unchanged drug), with 5% excreted in urine (3% as unchanged drug).

Half-Life: 114 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	2–4 hr	24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Thiamine deficiency (correct before starting therapy);
Severe hepatic impairment;
OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Cardiovascular risk factors (↑ risk of cardiovascular death, MI, stroke);
Current or past history of smoking (↑ risk of malignancy, cardiovascular death, MI, or stroke);
Known malignancy;
Severe renal impairment (↓ dose);
Pedi: Safety and efficacy not established in children.

Adv. Reactions/Side Effects ⬆ ⬇

CV: ARTERIAL THROMBOSIS, CARDIOVASCULAR DEATH, DEEP VEIN THROMBOSIS, MI

EENT: uveitis

F and E: hyponatremia

GI: constipation, diarrhea, ↑amylase, ↑lipase, ↑liver enzymes, nausea, vomiting, HEPATOTOXICITY

GU: ↑serum creatinine, dysuria

Hemat: anemia, neutropenia, thrombocytopenia

Metab: ↑weight

MS: muscle spasm, pain

Neuro: fatigue, dizziness, ENCEPHALOPATHY, headache, STROKE

Resp: PULMONARY EMBOLISM

Misc: SECONDARY MALIGNANCY

Interactions ⬆ ⬇

Drug-drug:

Strong CYP3A4 inhibitors, including ketoconazole, may ↑ levels and risk of toxicity; avoid concurrent use. If concurrent use unavoidable, ↓ fedratinib dose.
Dual CYP3A4 and CYP2C19 inhibitors, including fluconazole, may ↑ levels and risk of toxicity.
Moderate or strong CYP3A4 inducers may ↓ levels and effectiveness; avoid concurrent use.
May ↑ levels of CYP3A4 substrates, CYP2C19 substrates, and CYP2D6 substrates.

Route/Dosage ⬆ ⬇

PO (Adults ): Platelet count >50 × 10⁹/L: 400 mg once daily. Concurrent use of strong CYP3A4 inhibitor: 200 mg once daily.

Renal Impairment

PO (Adults ): CCr 15–29 mL/min and platelet count >50 × 10⁹/L: 200 mg once daily.

Availability ⬆ ⬇

Capsules: 100 mg

Assessment ⬆ ⬇

Monitor for signs/symptoms of encephalopathy (ataxia, mental status changes, nystagmus, diplopia, mental status change, confusion, memory impairment) during therapy. If encephalopathy suspected, discontinue fedratinib and begin IV thiamine.
Monitor for signs/symptoms of GI toxicity (nausea, vomiting, diarrhea) periodically during therapy. Nausea can be prophylactically treated with antiemetics. Use antidiarrheal agents at onset of diarrhea. For Grade ≥3 nausea, vomiting, or diarrhea unresponsive to treatments within 48 hr, hold fedratinib until Grade ≤1, then restart by ↓ dose by 100 mg/day.
Monitor for signs/symptoms of anemia (fatigue, dizziness, pale conjunctiva), thrombocytopenia (easy bruising, bleeding gums or nose, petechiae, blood in urine), and neutropenia (fatigue, sore throat, lymphadenopathy). Notify provider; may need to hold therapy and ↓ dose.
Monitor for signs/symptoms of uveitis including eye pain, light sensitivity, ↓/blurred vision, floaters, or irregular pupil shape.

Lab Test Considerations:

Monitor thiamine (vitamin B1) levels at baseline and periodically during therapy. Do not start therapy if thiamine is deficient; replenish thiamine levels before starting therapy.
- Monitor CBC, BUN, creatinine, hepatic function, amylase, and lipase at baseline and periodically during therapy
- May cause anemia, thrombocytopenia, and neutropenia. For Grade 4 thrombocytopenia or Grade 3 thrombocytopenia with active bleeding, hold dose until Grade ≤2. Restart dose at 100 mg daily below last dose given. For Grade 4 neutropenia, hold dose until resolved to Grade ≤2 or baseline, then restart by ↓ dose by 100 mg/day.
- May cause hepatotoxicty. For Grade ≥3 ↑ ALT, AST, or bilirubin, hold fedratinib until Grade ≤1, then restart by ↓ dose by 100 mg/day. Monitor ALT, AST, and bilirubin (total and direct) more frequently following dose ↓. If recurrence of a Grade ≥3 ↑ ALT, AST, or bilirubin, discontinue fedratinib.
- If Grade ≥3 amylase and/or lipase, hold fedratinib until Grade ≤1, then restart by ↓ dose by 100 mg/day.

Implementation ⬆ ⬇

Administer prophylactic oral thiamine 100 mg once daily during therapy for all patients.
Prophylactic antiemetics may be used during therapy.
PO: Administer without regard to food. Administering with a high-fat meal may ↓ nausea and vomiting.
- Patients who have difficulty swallowing or a nasogastric tube (French size 14 or 16), mix in a glass container with 180 mL of Ensure Plus liquid nutritional supplement at room temperature. Flush with 60 mL water after administration via nasogastric tube. Discard if not given within 2 hr.

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of fedratinib. If a dose is missed, take the next scheduled dose the following day. Do not double doses. Advise patient to read Patient Information before starting therapy.
Advise patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care provider before taking other medications.
Explain need for continued medical follow-up to assess effectiveness and possible side effects of medication. Periodic lab tests will be needed.
Advise patient to notify health care provider immediately if signs/symptoms of encephalopathy (confusion, memory problems, drowsiness, problems with balance and movement, difficulty walking, double or blurred vision, abnormal eye movements) occur.
Advise patient to notify health care provider if signs/symptoms of GI toxicity (diarrhea, nausea, or vomiting that does not respond to treatment; rapid weight loss or weight loss that does not get better with treatment) occur.
Advise patient to report signs/symptoms of anemia, thrombocytopenia, and neutropenia.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected and to avoid breastfeeding during therapy and for ≥1 mo after last dose.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇