Inrebic Dosage

Required Concomitant Medications

During treatment with INREBIC, all patients should receive prophylaxis with thiamine 100 mg orally daily.

Recommended Dosage

Conduct baseline testing of thiamine (Vitamin B1) levels prior to initiation of INREBIC.

The recommended dosage of INREBIC is 400 mg taken orally once daily for patients with a baseline platelet count of greater than or equal to 50 × 109/L.

INREBIC may be taken with or without food. Administration with a high fat meal may reduce the incidence of nausea and vomiting.

Modify the dose for patients using concomitant strong CYP3A4 inhibitors, and in patients with severe renal impairment (creatinine clearance (CLcr) 15 mL/min to 29 mL/min).

If a dose of INREBIC is missed, the next scheduled dose should be taken the following day.

Patients that are on treatment with ruxolitinib before the initiation of INREBIC must taper and discontinue according to the ruxolitinib prescribing information.

Monitoring for Safety

Obtain the following blood tests prior to starting treatment with INREBIC, periodically during treatment, and as clinically indicated:

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Thiamine (Vitamin B1) level

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Complete blood count with platelets

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Creatinine and BUN

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Hepatic panel

•

Amylase and lipase

Dose Modifications with Concomitant Use of Strong CYP3A4 Inhibitors

Reduce INREBIC dose when administering with strong CYP3A4 inhibitors to 200 mg once daily.

In cases where coadministration with a strong CYP3A4 inhibitor is discontinued, INREBIC dosage should be increased to 300 mg once daily during the first two weeks after discontinuation of the CYP3A4 inhibitor, and then to 400 mg once daily thereafter as tolerated.

Dose Modifications for Severe Renal Impairment

Reduce INREBIC dose to 200 mg once daily in patients with severe renal impairment (creatinine clearance (CLcr) 15 mL/min to 29 mL/min as estimated by Cockcroft-Gault (C-G) equation).

Dose Modifications for Adverse Reactions

Modify dose for hematologic and nonhematologic adverse reactions per Table 1 and Table 2. Discontinue INREBIC in patients unable to tolerate a dose of 200 mg daily. See Warnings and Precautions for other mitigating strategies.

Consider dose reductions for patients who become transfusion-dependent during treatment with INREBIC.

Management of Thiamine Levels and Wernicke's Encephalopathy (WE)

Assess thiamine levels and nutritional status prior to starting INREBIC. Do not start INREBIC in patients with thiamine deficiency. However, if thiamine levels are low, replete thiamine prior to starting treatment. While on INREBIC treatment all patients should receive prophylaxis with daily 100 mg oral thiamine and should have thiamine levels assessed as clinically indicated. If Wernicke's encephalopathy is suspected, immediately discontinue treatment with INREBIC and initiate parenteral thiamine treatment. Monitor until symptoms resolve or improve and thiamine levels normalize.