Basic knowledge about febuxostat.📃📃📃

Febuxostat is a xanthine oxidase inhibitor. It inhibits the production of uric acid. While allopurinol can only inhibit the reduced form of xanthine oxidase, febuxostat can inhibit both the reduced and oxidized forms of xanthine oxidase. Therefore, febuxostat's ability to lower uric acid is faster and stronger. 80% of blood uric acid is synthesized in the body, and only 20% is absorbed from food. Patients with gout need to control their blood uric acid within the target range (<360 μmol/mL) throughout their lives to reduce the frequency of gout attacks, prevent tophi formation, prevent bone destruction, and reduce the risk of death. Therefore, they may need to take long-term uric acid-lowering medications.

What are the indications for Febuxostat?

Allopurinol, febuxostat, and benzbromarone are recommended for patients with gout. However, febuxostat is not recommended for use in asymptomatic hyperuricemia. In patients with asymptomatic hyperuricemia in stages 3 and 4 chronic kidney disease, the dose of allopurinol needs to be adjusted and severe hypersensitivity reactions may occur. Therefore, febuxostat may be a better treatment. Febuxostat is indicated for the long-term treatment of hyperuricemia in patients with gout. However, it is not recommended for use in patients with asymptomatic hyperuricemia. Febuxostat has little effect on renal function. No dose adjustment is required in patients with renal insufficiency.

When should uric acid-lowering drugs be used?

Some guidelines recommend that patients with gout can start uric acid-lowering drug treatment after the acute gout attack is completely relieved for 2 to 4 weeks. This is because urate-lowering medications can worsen the symptoms of gouty arthritis. However, if gout attacks are frequent, uric acid-lowering medication can be started at the time of the gout attack. Therefore, they should not be used until the symptoms of acute inflammation of gouty arthritis have resolved. In addition, allopurinol is generally recommended as the first-choice uric acid-lowering drug, but HLA-B*5801 genotype monitoring should be performed before use. Allopurinol is contraindicated in patients with positive HLA-B*5801 genotype.

What is the dosage of Febuxostat?

Common tablet doses of febuxostat are 20mg, 40 mg and 80 mg. The recommended starting dose of febuxostat is 20 mg daily. Patients whose serum uric acid levels do not reach the target value after 2 to 4 weeks of treatment can be increased to 40 mg per day, with a maximum dose of 80 mg per day. Febuxostat tablets can usually be taken in split doses without affecting the effectiveness of the medicine. Its uric acid-lowering effect is not affected by food. 

What are the adverse effects of Febuxostat?

Common adverse reactions generally refer to adverse reactions that occur in at least 1% of patients and are at least 0.5% higher than those in the placebo group. Abnormal liver function, arthralgia, nausea, and rash are common adverse reactions of febuxostat. Abnormal liver function is the most common adverse reaction causing patients to discontinue febuxostat treatment. Therefore, patients should undergo a liver function test before doctors prescribe febuxostat. In addition, if patients experience fatigue, loss of appetite, right upper quadrant discomfort, soy sauce-colored urine or jaundice during the medication period, they should seek medical treatment in time.

Side effect	Placebo group	Allopurinol	Febuxostat
			40 mg/day	80 mg/day
Abnormal liver function	0.7%	4.2%	6.6%	4.6%
Arthralgia	0%	0.7%	1.1%	0.7%
Nausea	0.7%	0.8%	1.1%	1.3%
Rash	0.7%	1.6%	0.5%	1.6%

Febuxostat is more likely to increase the risk of cardiovascular death in patients with gout than allopurinol. Therefore, febuxostat should be used with caution in elderly patients with gout and cardiovascular and cerebrovascular diseases. Allopurinol is the first-line treatment for gout patients with severe cardiovascular disease (such as myocardial infarction, history of stroke, unstable angina). During the medication period, patients should seek medical attention immediately if they develop symptoms such as chest pain, shortness of breath, fast or irregular heartbeat, numbness or weakness on one side of the body, dizziness, difficulty speaking, or sudden severe headache.