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Vioxx: profile and news
Vioxx lawsuits dismissed 17 May 2006 Off-label drugs often prescribed, study shows 17 May 2006 Merck: Court Dismisses Holder Action Related To Vioxx 17 May 2006 In The Story Of Vioxx, A Media Angle May 15, 2006 Man seeking compensation for Vioxx disgusted at heart attack May 14, 2006 Canine version of Vioxx can be deadly May 14, 2006 Doctors Challenge Claims of Vioxx Study May 13, 2006 Cardiologist says Vioxx still a risk after stopping May 13, 2006 Doctors: New data show Vioxx remained dangerous at least one year ... May 13, 2006 Experts say Vioxx poses risks long after patients stop taking it May 14, 2006 Deramaxx, the Vioxx of Pet Medication May 13, 2006 Bush Uses FDA To Shield Big Pharma From Lawsuits May 14, 2006 Follow-Up Study on Vioxx Safety Is Disputed May 12, 2006 New Vioxx-related stroke data poses legal risk to Merck May 12, 2006 Merck Adds to Vioxx Data May 11, 2006 Study: Vioxx Users Not at Increased Risk May 11, 2006 Study: Vioxx Users Not at Increased Risk May 11, 2006 CORRECTED - Study suggests no added risk after stopping Vioxx May 12, 2006 Study Suggests Heart Risk Lingers After Vioxx Use Stops May 11, 2006 Doctors Challenge Claims of Vioxx Study May 12, 2006 No Added Risk Seen From Ending Vioxx Use May 11, 2006 Study: Vioxx Users Not at Increased Risk May 11, 2006 Study suggests no added risk after stopping Vioxx May 11, 2006 Judge Postpones Vioxx Trial in NJ May 10, 2006 Cardiologist says Vioxx still a risk after stopping May 12, 2006 Merck: No increased heart risk after Vioxx use is stopped May 11, 2006 Merck: Risks elevated for Vioxx patients May 12, 2006 Merck touts Vioxx analysis, but there are doubters May 11, 2006 Vioxx study says heart risk falls when drug is stopped May 12, 2006 Does Stopping Vioxx Stop the Risk? May 12, 2006 Study: Vioxx Users Not at Increased Risk May 11, 2006 Vioxx heart risk remains in 4-yr data May 11, 2006 Vioxx users not at risk of strokes after a year May 12, 2006 Merck Hopes New Study Will Help In Vioxx Defense May 12, 2006 Doctors challenge Merck reading of risk after Vioxx May 12, 2006 1 Vioxx trial delayed, another starting soon May 11, 2006 Merck releases new data on Vioxx May 11, 2006 Vioxx lawsuits place lives ahead of profits May 9, 2006 Vioxx on Trial May 12, 2006 Cardiologist says Vioxx still a risk after stopping (Reuters) May 12, 2006 Vioxx Heart Attacks May Occur in 2 Weeks, Study Says (Update2) May 2, 2006 New study may lead to more Vioxx suits May 3, 2006 President Bush can advance tort reform with Vioxx litigation May 3, 2006 Canadian warning adds to Merck's troubles over Vioxx May 2, 2006 Vioxx's risk high in first two weeks, study finds May 3, 2006 Other information Indication For the treatment of osteoarthritis, acute pain in adults and menstrual pain Pharmacology Rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is classified as a nonsteroidal anti-inflammatory drug (NSAID). Rofecoxib is used for its anti-inflammatory, analgesic, and antipyretic activities in the management of osteoarthritis (OA) and for the treatment of dysmenorrhea or acute pain. Unlike celecoxib, Rofecoxib lacks a sulfonamide chain and does not require CYP450 enzymes for metabolism. Mechanism Of Action Both COX-1 and COX-2 catalyze the conversion of arachidonic acid to prostaglandin (PG) H2, the precursor of PGs and thromboxane. Rofecoxib selectively inhibits the cyclooxygenase-2 (COX-2) enzyme, important for the mediation of inflammation and pain. Unlike non-selective NSAIDs, Rofecoxib does not inhibit platelet aggregation. Drug Category Anti-inflammatory Agents; Nonsteroidal Antiinflammatory Agents (NSAIDs); ATC:M01AH02 Brand Names/Synonyms CCRIS 8967; CHEMBANK1837; MK 0966; MK 0996; MK 966; MK 996; Rofecoxib; Vioxx Dosage Forms Tablets, oral suspension Absorption The mean oral bioavailability of VIOXX at therapeutically recommended doses of 12.5, 25, and 50 mg is approximately 93% Interactions -->Interactions for Rofecoxib: ACE inhibitors: Reports suggest that NSAIDs may diminish the antihypertensive effect of Angiotensin Converting Enzyme (ACE) inhibitors. In patients with mild to moderate hypertension, administration of 25 mg daily of VIOXX with the ACE inhibitor benazepril, 10 to 40 mg for 4 weeks, was associated with an average increase in mean arterial pressure of about 3 mm Hg compared to ACE inhibitor alone. This interaction should be given consideration in patients taking VIOXX concomitantly with ACE inhibitors. Aspirin Concomitant administration of low-dose aspirin with VIOXX may result in an increased rate of GI ulceration or other complications, compared to use of VIOXX alone. In a 12-week endoscopy study conducted in OA patients there was no difference in the cumulative incidence of endoscopic gastroduodenal ulcers in patients taking low-dose (81 mg) enteric coated aspirin plus VIOXX 25 mg daily, as compared to those taking ibuprofen 2400 mg daily alone. Patients taking low-dose aspirin plus ibuprofen were not studied. At steady state, VIOXX 50 mg once daily had no effect on the anti-platelet activity of low-dose (81 mg once daily) aspirin, as assessed by ex vivo platelet aggregation and serum TXB2 generation in clotting blood. Because of its lack of platelet effects, VIOXX is not a substitute for aspirin for cardiovascular prophylaxis. Therefore, in patients taking VIOXX, antiplatelet therapies should not be discontinued and should be considered in patients with an indication for cardiovascular prophylaxis. Prospective, long-term studies on concomitant administration of VIOXX and aspirin have not been conducted. Cimetidine Co-administration with high doses of cimetidine [800 mg twice daily] increased the Cmax of rofecoxib by 21%, the AUC0-120hr by 23% and the t1/2 by 15%. These small changes are not clinically significant and no dose adjustment is necessary. Digoxin Rofecoxib 75 mg once daily for 11 days does not alter the plasma concentration profile or renal elimination of digoxin after a single 0.5 mg oral dose. Furosemide Clinical studies, as well as post-marketing observations, have shown that NSAIDs can reduce the natriuretic effect of furosemide and thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis. Ketoconazole Ketoconazole 400 mg daily did not have any clinically important effect on the pharmacokinetics of rofecoxib. Lithium NSAIDs have produced an elevation of plasma lithium levels and a reduction in renal lithium clearance. In post-marketing experience there have been reports of increases in plasma lithium levels. Thus, when VIOXX and lithium are administered concurrently, subjects should be observed carefully for signs of lithium toxicity. Methotrexate VIOXX 12.5, 25, and 50 mg, each dose administered once daily for 7 days, had no effect on the plasma concentration of methotrexate as measured by AUC0-24hr in patients receiving single weekly methotrexate doses of 7.5 to 20 mg for rheumatoid arthritis. At higher than recommended doses, VIOXX 75 mg administered once daily for 10 days increased plasma concentrations by 23% as measured by AUC0-24hr in patients receiving methotrexate 7.5 to 15 mg/week for rheumatoid arthritis. At 24 hours postdose, a similar proportion of patients treated with methotrexate alone (94%) and subsequently treated with methotrexate co-administered with 75 mg of rofecoxib (88%) had methotrexate plasma concentrations below the measurable limit (5 ng/mL). Standard monitoring of methotrexate-related toxicity should be continued if VIOXX and methotrexate are administered concomitantly. Oral Contraceptives Rofecoxib did not have any clinically important effect on the pharmacokinetics of ethinyl estradiol and norethindrone. Prednisone/prednisolone Rofecoxib did not have any clinically important effect on the pharmacokinetics of prednisolone or prednisone. Rifampin Co-administration of VIOXX with rifampin 600 mg daily, a potent inducer of hepatic metabolism, produced an approximate 50% decrease in rofecoxib plasma concentrations. Therefore, a starting daily dose of 25 mg of VIOXX should be considered for the treatment of osteoarthritis when VIOXX is co-administered with potent inducers of hepatic metabolism. Theophylline VIOXX 12.5, 25, and 50 mg administered once daily for 7 days increased plasma theophylline concentrations (AUC(0-¥)) by 38 to 60% in healthy subjects administered a single 300-mg dose of theophylline. Adequate monitoring of theophylline plasma concentrations should be considered when therapy with VIOXX is initiated or changed in patients receiving theophylline. These data suggest that rofecoxib may produce a modest inhibition of cytochrome P450 (CYP) 1A2. Therefore, there is a potential for an interaction with other drugs that are metabolized by CYP 1A2 (e.g., amitriptyline, tacrine, and zileuton). Warfarin Anticoagulant activity should be monitored, particularly in the first few days after initiating or changing VIOXX therapy in patients receiving warfarin or similar agents, since these patients are at an increased risk of bleeding complications. In single and multiple dose studies in healthy subjects receiving both warfarin and rofecoxib, prothrombin time (measured as INR) was increased by approximately 8% to 11%. In post-marketing experience, bleeding events have been reported, predominantly in the elderly, in association with increases in prothrombin time in patients receiving VIOXX concurrently with warfarin. Chemical IUPAC Name 4-(4-methylsulfonylphenyl)-3-phenyl-5H-furan-2-one Chemical Formula C17H14O4S Half Life 17 hours Drug Type Approved Drug # Accession No APRD00151 CAS Registry Number 162011-90-7 |
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