Overview
11 DESCRIPTION Febuxostat is a xanthine oxidase inhibitor. The active ingredient in febuxostat tablets is 2-[3-cyano-4-(2-methylpropoxy) phenyl]-4-methylthiazole-5-carboxylic acid, with a molecular weight of 316.38. The molecular formula is C 16 H 16 N 2 O 3 S. The chemical structure is: Febuxostat is a non-hygroscopic, white to off-white crystalline powder that is freely soluble in...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Febuxostat, a xanthine oxidase inhibitor, achieves its therapeutic effect by decreasing serum uric acid. Febuxostat is not expected to inhibit other enzymes involved in purine and pyrimidine synthesis and metabolism at therapeutic concentrations. 12.2 Pharmacodynamics Effect on Uric Acid and Xanthine Concentrations In healthy patients, febuxostat resulted in a dose dependent decrease in 24-hour mean serum uric acid concentrations and an increase in 24-hour mean serum xanthine concentrations. In addition, there was a decrease in the total daily urinary uric acid excretion. Also, there was an increase in total daily urinary xanthine excretion.
Indications
- 1 INDICATIONS AND USAGE Febuxostat is a xanthine oxidase (XO) inhibitor indicated for the chronic management of hyperuricemia in adult patients with gout who have an inadequate response to a maximally titrated dose of allopurinol, who are intolerant to allopurinol, or for whom treatment with allopurinol is not advisable. Limitations of Use : Febuxostat tablets are not recommended for the treatment of asymptomatic hyperuricemia.
Common Doses
- 40 mg
- 80 mg
- 6 mg
Dosage
2 DOSAGE AND ADMINISTRATION Recommended dosage is 40 mg or 80 mg once daily. The recommended starting dosage is 40 mg once daily. For patients who do not achieve a serum uric acid (sUA) less than 6 mg/dL after 2 weeks, the recommended dosage is 80 mg once daily. ( 2.1 ) Patients with severe renal impairment: Limit the dosage to 40 mg once daily. ( 2.2 , 8.6 ) Flare prophylaxis is recommended upon initiation of febuxostat tablets. ( 2.4 ) Can be administered without regard to food or antacid use. ( 2.1 ) 2.
Black Box Warning
WARNING: CARDIOVASCULAR DEATH Gout patients with established cardiovascular (CV) disease treated with febuxostat tablets had a higher rate of CV death compared to those treated with allopurinol in a CV outcomes study [see Warnings and Precautions (5.1) ] . Consider the risks and benefits of febuxostat tablets when deciding to prescribe or continue patients on febuxostat tablets. Febuxostat tablets should only be used in patients who have an inadequate response to a maximally titrated dose of allopurinol, who are intolerant to allopurinol, or for whom treatment with allopurinol is not...
Contraindications
- 4 CONTRAINDICATIONS Febuxostat tablets are contraindicated in patients being treated with azathioprine or mercaptopurine [see Drug Interactions (7) ] . Febuxostat tablets are contraindicated in patients being treated with azathioprine or mercaptopurine. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are described elsewhere in the prescribing information: Cardiovascular Death [see Warnings and Precautions (5.1) ] Hepatic Effects [see Warnings and Precautions (5.3) ] Serious Skin Reactions [see Warnings and Precautions (5.4) ] Adverse reactions in ≥ 1% of patients treated with febuxostat are liver function abnormalities, nausea, arthralgia, and rash. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.
Interactions
- 7 DRUG INTERACTIONS Concomitant administration of febuxostat with XO substrate drugs, azathioprine or mercaptopurine could increase plasma concentrations of these drugs resulting in severe toxicity. ( 7 ) 7.1 Xanthine Oxidase Substrate Drugs Febuxostat is an XO inhibitor. Based on a drug interaction study in healthy patients, febuxostat altered the metabolism of theophylline (a substrate of XO) in humans [see Clinical Pharmacology (12.3) ]. Therefore, use with caution when coadministering febuxostat with theophylline.