Goustat

Goustat tablets are indicated for the chronic management of hyperuricemia in patients with gout. Goustat tablets are not recommended for the treatment of asymptomatic hyperuricemia.

Febuxostat is a non-purine, selective xanthine oxidase (XO) inhibitor. It decreases serum uric acid level by inhibiting xanthine oxidase, which is responsible for uric acid production. Xanthine oxidase breaks down hypoxanthine to xanthine and thus to uric acid. Febuxostat is not expected to inhibit other enzymes involved in purine and pyrimidine synthesis and metabolism at therapeutic concentrations.

The recommended starting dose : Febuxostat 40 mg tablet once daily. For patients who do not achieve a serum uric acid less than 6 mg per dL after 2 weeks with Febuxostat 40 mg tablet, One Febuxostat 80 mg tablet once daily is recommended. If serum uric acid less than 6 mg per dL after 2-4 weeks with Xanuric 80 (Febuxostat 80mg) tablet, then one Febuxostat 120 mg tablet once daily is recommended. Tumor Lysis Syndrome : The recommended dose is one Febuxostat 120 mg tablet once daily. Febuxostat 120 mg tablet should be started two days before the beginning of cytotoxic therapy and continued for a minimum of 7 days. However treatment may be prolonged up to 9 days according to chemotherapy duration as per clinical judgment. Gout Flares : Gout flares may occur after initiation of Feboxostat tablets due to changing serum uric acid levels resulting in mobilization of urate from tissue deposits. Flare prophylaxis with a non-steroidal anti-inflammatory drug (NSAID) or colchicine is recommended upon initiation of Febuxostat tablets. If a gout flare occurs during treatment, Feboxostat tablets need not be discontinued. The gout flare should be managed concurrently, as appropriate for the individual patient. Renal impairment : No dose adjustment is necessary when administering Febuxostat in patients with mild to moderate renal impairment. Hepatic impairment : No dose adjustment is necessary in patients with mild to moderate hepatic impairment. Pediatric Use : Safety and effectiveness in pediatric patients under 18 years of age have not been established

Mercaptopurine/Azathioprine : On the basis of the mechanism of action of Goustat on XO inhibition concomitant use is not recommended. Inhibition of XO by Goustat may cause increased plasma concentrations of these drugs leading to toxicity. Rosiglitazone/CYP2C8 substrates : Co-administration of Goustat with rosiglitazone or other CYP2C8 substrates is not expected to require any dose adjustment for those compounds. Naproxen and other inhibitors of glucuronidation : Goustat metabolism depends on Uridine Glucuronosyl Transferase (UGT) enzymes. Medicinal products that inhibit glucuronidation, such as NSAIDs and probenecid, could in theory affect the elimination of Goustat. Goustat can be co-administered with naproxen with no dose adjustment of Goustat or naproxen being necessary. Inducers of glucuronidation : Potent inducers of UGT enzymes might possibly lead to increased metabolism and decreased efficacy of Goustat. Monitoring of serum uric acid is therefore recommended 1-2 weeks after start of treatment with a potent inducer of glucuronidation. Conversely, cessation of treatment of an inducer might lead to increased plasma levels of Goustat. Colchicine/ Indometacin/ Hydrochlorothiazide/ Warfarin : Goustat can be co-administered with colchicine or indomethacin with no dose adjustment of Goustat. No dose adjustment is necessary for hydrochlorothiazide or warfarin when administered with Goustat . Antacids : Concomitant ingestion of an antacid containing magnesium hydroxide and aluminium hydroxide has been shown to delay absorption of Goustat  (approximately 1 hour) and to cause a 32% decrease in Cmax, but no significant change in AUC was observed. Therefore, Goustat  may be taken without regard to antacid use.

Febuxostat is contraindicated in patients being treated with azathioprine, mercaptopurine, or theophylline.

The most commonly reported adverse reactions are gout flares, liver function abnormalities, diarrhoea, nausea, headache, rash and oedema. These adverse reactions were mostly mild or moderate in severity. Rare serious hypersensitivity reactions to Goustat have observed.

Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Febuxostat should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether this drug is excreted in human milk. Caution should be exercised when Febuxostat is administered to a nursing woman.

Gout Flare : An increase in gout flares is frequently observed during initiation of anti-hyperuricemic agents, including Goustat. If a gout flare occurs during treatment, Goustat need not be discontinued. Prophylactic therapy (i.e., non-steroidal anti-inflammatory drug (NSAID) or colchicine upon initiation of treatment) may be beneficial for up to six months. Cardiovascular Events : A higher rate of cardiovascular thromboembolic events was observed in patients treated with Goustat than allopurinol in clinical trials. Monitor for signs and symptoms of MI and stroke. Liver Enzyme Elevation : Transaminase elevations have been observed in Goustat -treated patients. Monitor liver function tests periodically.

Febustat was studied in healthy subjects in doses up to 300 mg daily for seven days without evidence of dose-limiting toxicities.

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.