Bextra

In the U.S.

• Bextra

Available Dosage Forms:

• Tablet

Therapeutic Class: Analgesic

Pharmacologic Class: Cyclooxygenase-2 Inhibitor

Serious Skin Reactions

• Serious skin reactions (e.g., toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme) have been reported in patients receiving Bextra. Some of these reactions have resulted in death.
• Patients appear to be at higher risk for these events within the first 2 weeks of treatment, but these may occur at any time during treatment.
• The reported rate of these serious skin events appears to be greater for Bextra as compared to other COX-2 agents.
• Bextra should be discontinued at the first appearance of skin rash, mucosal lesions, or any other sign of hypersensitivity.

(See WARNINGS – Serious Skin Reactions)

Mechanism of Action

Valdecoxib is a nonsteroidal anti-inflammatory drug (NSAID) that exhibits anti-inflammatory, analgesic and antipyretic properties in animal models. The mechanism of action is believed to be due to inhibition of prostaglandin synthesis primarily through inhibition of cyclooxygenase-2 (COX-2). At therapeutic plasma concentrations in humans valdecoxib does not inhibit cyclooxygenase-1 (COX-1).

Pharmacokinetics

Absorption

Valdecoxib achieves maximal plasma concentrations in approximately 3 hours. The absolute bioavailability of valdecoxib is 83% following oral administration of Bextra compared to intravenous infusion of valdecoxib.

Dose proportionality was demonstrated after single doses (1–400 mg) of valdecoxib. With multiple doses (up to 100 mg/day for 14 days), valdecoxib exposure as measured by the AUC, increases in a more than proportional manner at doses above 10 mg BID. Steady state plasma concentrations of valdecoxib are achieved by day 4.

The steady state pharmacokinetic parameters of valdecoxib in healthy male subjects are shown in Table 1.

Table 1 Mean (SD) Steady State Pharmacokinetic Parameters

Steady State Pharmacokinetic Parameters after Valdecoxib 10 mg Once Daily for 14 Days	Healthy Male Subjects (n=8, 20 to 42 yr.)
AUC(0–24hr) (hr∙ng/mL)	1479.0 (291.9)
Cmax (ng/mL)	161.1 (48.1)
Tmax (hr)	2.25 (0.71)
Cmin (ng/mL)	21.9 (7.68)
Elimination Half-life (hr)	8.11 (1.32)

No clinically significant age or gender differences were seen in pharmacokinetic parameters that would require dosage adjustments.

Effect of Food and Antacid

Bextra can be taken with or without food. Food had no significant effect on either the peak plasma concentration (Cmax) or extent of absorption (AUC) of valdecoxib when Bextra was taken with a high fat meal. The time to peak plasma concentration (Tmax), however, was delayed by 1–2 hours. Administration of Bextra with antacid (aluminum/magnesium hydroxide) had no significant effect on either the rate or extent of absorption of valdecoxib.

Distribution

Plasma protein binding for valdecoxib is about 98% over the concentration range (21–2384 ng/mL). Steady state apparent volume of distribution (Vss/F) of valdecoxib is approximately 86 L after oral administration. Valdecoxib and its active metabolite preferentially partition into erythrocytes with a blood to plasma concentration ratio of about 2.5:1. This ratio remains approximately constant with time and therapeutic blood concentrations.

Metabolism

In humans, valdecoxib undergoes extensive hepatic metabolism involving both P450 isoenzymes (3A4 and 2C9) and non-P450 dependent pathways (i.e., glucuronidation). Concomitant administration of Bextra with known CYP 3A4 and 2C9 inhibitors (e.g., fluconazole and ketoconazole) can result in increased plasma exposure of valdecoxib (see PRECAUTIONS Drug Interactions).

One active metabolite of valdecoxib has been identified in human plasma at approximately 10% the concentration of valdecoxib. This metabolite, which is a less potent COX-2 specific inhibitor than the parent, also undergoes extensive metabolism and constitutes less than 2% of the valdecoxib dose excreted in the urine and feces. Due to its low concentration in the systemic circulation, it is not likely to contribute significantly to the efficacy profile of Bextra.

Excretion

Valdecoxib is eliminated predominantly via hepatic metabolism with less than 5% of the dose excreted unchanged in the urine and feces. About 70% of the dose is excreted in the urine as metabolites, and about 20% as valdecoxib N-glucuronide. The apparent oral clearance (CL/F) of valdecoxib is about 6 L/hr. The mean elimination half-life (T1/2) ranges from 8–11 hours, and increases with age.

Special Populations

Geriatric

In elderly subjects (> 65 years), weight-adjusted steady state plasma concentrations (AUC(0–12hr)) are about 30% higher than in young subjects. No dose adjustment is needed based on age.

Pediatric

Bextra has not been investigated in pediatric patients below 18 years of age.

Race

Pharmacokinetic differences due to race have not been identified in clinical and pharmacokinetic studies conducted to date.

Hepatic Insufficiency

Valdecoxib plasma concentrations are significantly increased (130%) in patients with moderate (Child-Pugh Class B) hepatic impairment. In clinical trials, doses of Bextra above those recommended have been associated with fluid retention. Hence, treatment with Bextra should be initiated with caution in patients with mild to moderate hepatic impairment and fluid retention. The use of Bextra in patients with severe hepatic impairment (Child-Pugh Class C) is not recommended.

Renal Insufficiency

The pharmacokinetics of valdecoxib have been studied in patients with varying degrees of renal impairment. Because renal elimination of valdecoxib is not important to its disposition, no clinically significant changes in valdecoxib clearance were found even in patients with severe renal impairment or in patients undergoing renal dialysis. In patients undergoing hemodialysis the plasma clearance (CL/F) of valdecoxib was similar to the CL/F found in healthy elderly subjects (CL/F about 6 to 7 L/hr.) with normal renal function (based on creatinine clearance).

NSAIDs have been associated with worsening renal function and use in advanced renal disease is not recommended (see PRECAUTIONS Renal Effects).

Drug Interactions

For quantitative information on the following drug interaction studies, see PRECAUTIONS Drug Interactions.

General

Valdecoxib undergoes both P450 (CYP) dependent and non-P450 dependent (glucuronidation) metabolism. In vitro studies indicate that valdecoxib is not a significant inhibitor of CYP 1A2, 3A4, or 2D6 and is a weak inhibitor of CYP 2C9 and a weak to moderate inhibitor of CYP 2C19 at therapeutic concentrations. The P450-mediated metabolic pathway of valdecoxib predominantly involves the 3A4 and 2C9 isozymes. Using prototype inhibitors and substrates of these isozymes, the following results were obtained. Coadministration of a known inhibitor of CYP 2C9/3A4 (fluconazole) and a CYP 3A4 inhibitor (ketoconazole) enhanced the total plasma exposure (AUC) of valdecoxib. Coadministration of valdecoxib with a CYP 3A4 inducer (phenytoin) decreased total plasma exposure (AUC) of valdecoxib. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with warfarin (a CYP 2C9 substrate) caused a small, but statistically significant increase in plasma exposures of R-warfarin and S-warfarin, and also in the pharmacodynamic effects (International Normalized Ratio-INR) of warfarin. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with diazepam (a CYP 2C19/3A4 substrate) resulted in increased exposure of diazepam, but not its major metabolite, desmethyldiazepam. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with glyburide (a CYP 2C9 substrate) (40 mg valdecoxib QD with 10 mg glyburide BID) resulted in increased exposure of glyburide. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with an oral contraceptive, 1 mg norethindrone/0.035 mg ethinyl estradiol (CYP 3A4 substrates), resulted in increased exposure of both norethindrone and ethinyl estradiol. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with omeprazole (a CYP 3A4/2C19 substrate) caused an increase in omeprazole exposure. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with dextromethorphan (a CYP 2D6/3A4 substrate) resulted in an increase in dextromethorphan plasma levels above those seen in subjects with normal levels of CYP 2D6. Even so these levels were almost 5-fold lower than those seen in CYP 2D6 poor metabolizers. (See PRECAUTIONS Drug Interactions.)

Coadministration of valdecoxib with phenytoin (a CYP 2C9/2C19 substrate) did not affect the pharmacokinetics of phenytoin.

Coadministration of valdecoxib, or its injectable prodrug, with substrates of CYP 2C9 (propofol) and CYP 3A4 (midazolam, alfentanil, fentanyl) did not inhibit the metabolism of these substrates.

General

Bextra Tablets cannot be expected to substitute for corticosteroids or to treat corticosteroid insufficiency. Abrupt discontinuation of corticosteroids may lead to exacerbation of corticosteroid-responsive illness. Patients on prolonged corticosteroid therapy should have their therapy tapered slowly if a decision is made to discontinue corticosteroids.

The pharmacological activity of valdecoxib in reducing fever and inflammation may diminish the utility of these diagnostic signs in detecting complications of presumed noninfectious, painful conditions.

Hepatic Effects

Borderline elevations of one or more liver tests may occur in up to 15% of patients taking NSAIDs. Notable elevations of ALT or AST (approximately three or more times the upper limit of normal) have been reported in approximately 1% of patients in clinical trials with NSAIDs. These laboratory abnormalities may progress, may remain unchanged, or may remain transient with continuing therapy. Rare cases of severe hepatic reactions, including jaundice and fatal fulminant hepatitis, liver necrosis and hepatic failure (some with fatal outcome) have been reported with NSAIDs. In controlled clinical trials of valdecoxib, the incidence of borderline (defined as 1.2- to 3.0-fold) elevations of liver tests was 8.0% for valdecoxib and 8.4% for placebo, while approximately 0.3% of patients taking valdecoxib, and 0.2% of patients taking placebo, had notable (defined as greater than 3-fold) elevations of ALT or AST.

A patient with symptoms and/or signs suggesting liver dysfunction, or in whom an abnormal liver test has occurred, should be monitored carefully for evidence of the development of a more severe hepatic reaction while on therapy with Bextra. If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash), Bextra should be discontinued.

Renal Effects

Long-term administration of NSAIDs has resulted in renal papillary necrosis and other renal injury. Renal toxicity has also been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion. In these patients, administration of a nonsteroidal anti-inflammatory drug may cause a dose-dependent reduction in prostaglandin formation and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk of this reaction are those with impaired renal function, heart failure, liver dysfunction, those taking diuretics and Angiotensin Converting Enzyme (ACE) inhibitors, and the elderly. Discontinuation of NSAID therapy is usually followed by recovery to the pretreatment state.

Caution should be used when initiating treatment with Bextra in patients with considerable dehydration. It is advisable to rehydrate patients first and then start therapy with Bextra. Caution is also recommended in patients with preexisting kidney disease. (See WARNINGS Advanced Renal Disease.)

Hematological Effects

Anemia is sometimes seen in patients receiving Bextra. Patients on long-term treatment with Bextra should have their hemoglobin or hematocrit checked if they exhibit any signs or symptoms of anemia.

Bextra does not generally affect platelet counts, prothrombin time (PT), or activated partial thromboplastin time (APTT), and does not appear to inhibit platelet aggregation at indicated dosages (see CLINICAL STUDIES Safety Studies Platelets).

Fluid Retention and Edema

Fluid retention and edema have been observed in some patients taking Bextra (see ADVERSE REACTIONS). Therefore, Bextra should be used with caution in patients with fluid retention, hypertension, or heart failure.

Preexisting Asthma

Patients with asthma may have aspirin-sensitive asthma. The use of aspirin in patients with aspirin-sensitive asthma has been associated with severe bronchospasm, which can be fatal. Since cross reactivity, including bronchospasm, between aspirin and other nonsteroidal anti-inflammatory drugs has been reported in such aspirin-sensitive patients, Bextra should not be administered to patients with this form of aspirin sensitivity and should be used with caution in patients with preexisting asthma.

Information for Patients

Bextra can cause GI discomfort and, rarely, more serious GI side effects, which may result in hospitalization and even fatal outcomes. Although serious GI tract ulcerations and bleeding can occur without warning symptoms, patients should be alert for the signs and symptoms of ulcerations and bleeding, and should ask for medical advice when observing any indicative sign or symptoms. Patients should be apprised of the importance of this follow-up (see WARNINGS Gastrointestinal (GI) Effects Risk of GI Ulceration, Bleeding, and Perforation).

Patients should report to their physicians, signs or symptoms of gastrointestinal ulceration or bleeding, weight gain, or edema.

Patients should be instructed to discontinue treatment and seek medical attention at the first signs of a skin reaction (pruritus, rash, erythema, or mucosal lesions) (see WARNINGS Serious Skin Reactions).

Patients should also be instructed to seek immediate emergency help in the case of an anaphylactoid reaction (see WARNINGS Anaphylactoid Reactions).

Patients should be informed of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, pruritus, jaundice, right upper quadrant tenderness, and flu-like symptoms). If these occur, patients should be instructed to stop therapy and seek immediate medical attention.

In late pregnancy, Bextra should be avoided because it may cause premature closure of the ductus arteriosus.

Laboratory Tests

Because serious GI tract ulcerations and bleeding can occur without warning symptoms, physicians should monitor for signs and symptoms of GI bleeding.

Drug Interactions

The drug interaction studies with valdecoxib were performed both with valdecoxib and a rapidly hydrolyzed intravenous prodrug form. The results from trials using the intravenous prodrug are reported in this section as they relate to the role of valdecoxib in drug interactions.

General

In humans, valdecoxib metabolism is predominantly mediated via CYP 3A4 and 2C9 with glucuronidation being a further (20%) route of metabolism. In vitro studies indicate that valdecoxib is a moderate inhibitor of CYP 2C19 (IC50 = 6 µg/mL or 19 µM) and 2C9 (IC50 = 13 µg/mL or 41 µM), and a weak inhibitor of CYP 2D6 (IC50 = 31 µg/mL or 100 µM) and 3A4 (IC50 = 44 µg/mL or 141 µM).

Aspirin

Concomitant administration of aspirin with valdecoxib may result in an increased risk of GI ulceration and complications compared to valdecoxib alone. Because of its lack of anti-platelet effect valdecoxib is not a substitute for aspirin for cardiovascular prophylaxis.

In a parallel group drug interaction study comparing the intravenous prodrug form of valdecoxib at 40 mg BID (n=10) vs placebo (n=9), valdecoxib had no effect on in vitro aspirin-mediated inhibition of arachidonate- or collagen-stimulated platelet aggregation.

Methotrexate

Valdecoxib 10 mg BID did not show a significant effect on the plasma exposure or renal clearance of methotrexate.

ACE-inhibitors

Reports suggest that NSAIDs may diminish the antihypertensive effect of ACE-inhibitors. This interaction should be given consideration in patients taking Bextra concomitantly with ACE-inhibitors.

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.

Anticonvulsants (Phenytoin)

Steady state plasma exposure (AUC) of valdecoxib (40 mg BID for 12 days) was decreased by 27% when coadministered with multiple doses (300 mg QD for 12 days) of phenytoin (a CYP 3A4 inducer). Patients already stabilized on valdecoxib should be closely monitored for loss of symptom control with phenytoin coadministration. Valdecoxib did not have a statistically significant effect on the pharmacokinetics of phenytoin (a CYP 2C9 and CYP 2C19 substrate).

Drug interaction studies with other anticonvulsants have not been conducted. Routine monitoring should be performed when therapy with Bextra is either initiated or discontinued in patients on anticonvulsant therapy.

Dextromethorphan

Dextromethorphan is primarily metabolized by CYP 2D6 and to a lesser extent by 3A4. Coadministration with valdecoxib (40 mg BID for 7 days) resulted in a significant increase in dextromethorphan plasma levels suggesting that, at these doses, valdecoxib is a weak inhibitor of 2D6. Even so, dextromethorphan plasma concentrations in the presence of high doses of valdecoxib were almost 5-fold lower than those seen in CYP 2D6 poor metabolizers suggesting that dose adjustment is not necessary.

Lithium

Valdecoxib 40 mg BID for 7 days produced significant decreases in lithium serum clearance (25%) and renal clearance (30%) with a 34% higher serum exposure compared to lithium alone. Lithium serum concentrations should be monitored closely when initiating or changing therapy with Bextra in patients receiving lithium. Lithium carbonate (450 mg BID for 7 days) had no effect on valdecoxib pharmacokinetics.

Warfarin

The effect of valdecoxib on the anticoagulant effect of warfarin (1–8 mg/day) was studied in healthy subjects by coadministration of Bextra 40 mg BID for 7 days. Valdecoxib caused a statistically significant increase in plasma exposures of R-warfarin and S-warfarin (12% and 15%, respectively), and in the pharmacodynamic effects (prothrombin time, measured as INR) of warfarin. While mean INR values were only slightly increased with coadministration of valdecoxib, the day-to-day variability in individual INR values was increased. Anticoagulant therapy should be monitored, particularly during the first few weeks, after initiating therapy with Bextra in patients receiving warfarin or similar agents.

Fluconazole and Ketoconazole

Ketoconazole and fluconazole are predominantly CYP 3A4 and 2C9 inhibitors, respectively. Concomitant single dose administration of valdecoxib 20 mg with multiple doses of ketoconazole and fluconazole produced a significant increase in exposure of valdecoxib. Plasma exposure (AUC) to valdecoxib was increased 62% when coadministered with fluconazole and 38% when coadministered with ketoconazole.

Glyburide

Glyburide is a CYP 2C9 substrate. Coadministration of valdecoxib (10 mg BID for 7 days) with glyburide (5 mg QD or 10 mg BID) did not affect the pharmacokinetics (exposure) of glyburide. Coadministration of valdecoxib (40 mg BID (day 1) and 40 mg QD (days 2–7)) with glyburide (5 mg QD) did not affect either the pharmacokinetics (exposure) or the pharmacodynamics (blood glucose and insulin levels) of glyburide. Coadministration of valdecoxib (40 mg BID (day 1) and 40 mg QD (days 2–7)) with glyburide (10 mg glyburide BID) resulted in 21% increase in glyburide AUC(0–12hr) and a 16% increase in glyburide Cmax leading to a 16%decrease in glucose AUC(0–24hr). Insulin parameters were not affected. Because changes in glucose concentrations with valdecoxib coadministration were within the normal variability and individual glucose concentrations were above or near 70 mg/dL, dose adjustment for glyburide (5 mg QD and 10 mg BID) with valdecoxib coadministration (up to 40 mg QD) is not indicated. Coadministration of glyburide with doses higher than 40 mg valdecoxib (e.g., 40 mg BID) has not been studied.

Omeprazole

Omeprazole is a CYP 3A4 substrate and CYP 2C19 substrate and inhibitor. Valdecoxib steady state plasma concentrations (40 mg BID) were not affected significantly with multiple doses of omeprazole (40 mg QD). Coadministration with valdecoxib increased exposure of omeprazole (AUC) by 46%. Drugs whose absorption is sensitive to pH may be negatively impacted by concomitant administration of omeprazole and valdecoxib. However, because higher doses (up to 360 mg QD) of omeprazole are tolerated in Zollinger-Ellison (ZE) patients, no dose adjustment for omeprazole is recommended at current doses. Coadministration of valdecoxib with doses higher than 40 mg QD omeprazole has not been studied.

Oral Contraceptives

Valdecoxib (40 mg BID) did not induce the metabolism of the combination oral contraceptive norethindrone/ethinyl estradiol (1 mg/0.035 mg combination, Ortho-Novum 1/35®). Coadministration of valdecoxib and Ortho-Novum 1/35® increased the exposure of norethindrone and ethinyl estradiol by 20% and 34%, respectively. Although there is little risk for loss of contraceptive efficacy, the clinical significance of these increased exposures in terms of safety is not known. These increased exposures of norethindrone and ethinyl estradiol should be taken into consideration when selecting an oral contraceptive for women taking valdecoxib.

Diazepam

Diazepam (Valium®) is a CYP 3A4 and CYP 2C19 substrate. Plasma exposure of diazepam (10 mg BID) was increased by 28% following administration of valdecoxib (40 mg BID) for 12 days, while plasma exposure of valdecoxib (40 mg BID) was not substantially increased following administration of diazepam (10 mg BID) for 12 days. Although the magnitude of changes in diazepam plasma exposure when coadministered with valdecoxib were not sufficient to warrant dosage adjustments, patients may experience enhanced sedative side effects caused by increased exposure of diazepam under this circumstance. Patients should be cautioned against engaging in hazardous activities requiring complete mental alertness such as operating machinery or driving a motor vehicle.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Valdecoxib was not carcinogenic in rats given oral doses up to 7.5 mg/kg/day for males and 1.5 mg/kg/day for females (equivalent to approximately 2- to 6-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)) or in mice given oral doses up to 25 mg/kg/day for males and 50 mg/kg/day for females (equivalent to approximately 0.6- to 2.4-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)) for two years.

Valdecoxib was not mutagenic in an Ames test or a mutation assay in Chinese hamster ovary (CHO) cells, nor was it clastogenic in a chromosome aberration assay in CHO cells or in an in vivo micronucleus test in rat bone marrow.

Valdecoxib did not impair male rat fertility at oral doses up to 9.0 mg/kg/day (equivalent to approximately 3- to 6-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)). In female rats, a decrease in ovulation with increased pre- and post-implantation loss resulted in decreased live embryos/fetuses at doses ≥2 mg/kg/day (equivalent to approximately 2-fold human exposure at 20 mg QD as measured by the AUC(0–24hr) for valdecoxib). The effects on female fertility were reversible. This effect is expected with inhibition of prostaglandin synthesis and is not the result of irreversible alteration of female reproductive function.

Pregnancy

Teratogenic Effects

Pregnancy Category C

The incidence of fetuses with skeletal anomalies such as semi-bipartite thoracic vertebra centra and fused sternebrae was slightly higher in rabbits at an oral dose of 40 mg/kg/day (equivalent to approximately 72-fold human exposures at 20 mg QD as measured by the AUC(0–24hr)) throughout organogenesis. Valdecoxib was not teratogenic in rabbits up to an oral dose of 10 mg/kg/day (equivalent to approximately 8-fold human exposures at 20 mg QD as measured by the AUC(0–24hr)).

Valdecoxib was not teratogenic in rats up to an oral dose of 10 mg/kg/day (equivalent to approximately 19-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)). There are no studies in pregnant women. However, valdecoxib crosses the placenta in rats and rabbits. Bextra should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Non-teratogenic Effects

Valdecoxib caused increased pre- and post-implantation loss with reduced live fetuses at oral doses ≥10 mg/kg/day (equivalent to approximately 19-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)) in rats and an oral dose of 40 mg/kg/day (equivalent to approximately 72-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)) in rabbits throughout organogenesis. In addition, reduced neonatal survival and decreased neonatal body weight when rats were treated with valdecoxib at oral doses ≥6 mg/kg/day (equivalent to approximately 7-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)) throughout organogenesis and lactation period. No studies have been conducted to evaluate the effect of valdecoxib on the closure of the ductus arteriosus in humans. Therefore, as with other drugs known to inhibit prostaglandin synthesis, use of Bextra during the third trimester of pregnancy should be avoided.

Labor and Delivery

Valdecoxib produced no evidence of delayed labor or parturition at oral doses up to 10 mg/kg/day in rats (equivalent to approximately 19-fold human exposure at 20 mg QD as measured by the AUC(0–24hr)). The effects of Bextra on labor and delivery in pregnant women are unknown.

Nursing Mothers

Valdecoxib and its active metabolite are excreted in the milk of lactating rats. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, and because of the potential for adverse reactions in nursing infants from Bextra, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother and the importance of nursing to the infant.

Pediatric Use

Safety and effectiveness of Bextra in pediatric patients below the age of 18 years have not been evaluated.

Geriatric Use

Of the patients who received Bextra in arthritis clinical trials of three months duration, or greater, approximately 2100 were 65 years of age or older, including 570 patients who were 75 years or older. No overall differences in effectiveness were observed between these patients and younger patients.

Symptoms following acute NSAID overdoses are usually limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which are generally reversible with supportive care. Gastrointestinal bleeding can occur. Hypertension, acute renal failure, respiratory depression and coma may occur, but are rare.

Anaphylactoid reactions have been reported with therapeutic ingestion of NSAIDs, and may occur following an overdose.

Patients should be managed by symptomatic and supportive care following an NSAID overdose. There are no specific antidotes. Hemodialysis removed only about 2% of administered valdecoxib from the systemic circulation of 8 patients with end-stage renal disease and, based on its degree of plasma protein binding (>98%), dialysis is unlikely to be useful in overdose. Forced diuresis, alkalinization of urine, or hemoperfusion also may not be useful due to high protein binding.

Osteoarthritis and Adult Rheumatoid Arthritis

The recommended dose of Bextra Tablets for the relief of the signs and symptoms of arthritis is 10 mg once daily.

Primary Dysmenorrhea

The recommended dose of Bextra Tablets for treatment of primary dysmenorrhea is 20 mg twice daily, as needed.

The manufacturer of Bextra has announced the voluntary withdrawal of the drug from the U.S. market. This withdrawal is due to safety concerns of an increased risk of cardiovascular events (including heart attack and stroke) in patients taking non-steroidal anti-inflammatory drugs (Bextra is a "COX-2" selective non-steroidal anti-inflammatory drug) and safety concerns of an increased risk of rare but serious skin reactions in patients taking Bextra.

Do not take Bextra without first talking to your doctor if you have experienced asthma, hives, or an allergic reaction after taking a sulfa-based medication such as sulfamethoxazole (Bactrim, Septra, Gantanol, and others) or sulfisoxazole (Gantrisin); aspirin; or another NSAID such as celecoxib (Celebrex), ibuprofen (Motrin, Advil, Nuprin, and others), naproxen (Aleve, Naprosyn, Anaprox), ketoprofen (Orudis KT, Orudis, Oruvail), diclofenac (Voltaren, Cataflam), diflunisal (Dolobid), etodolac (Lodine, Lodine XL), fenoprofen (Nalfon), flurbiprofen (Ansaid), indomethacin (Indocin), ketorolac (Toradol), meloxicam (Mobic), nabumetone (Relafen), oxaprozin (Daypro), piroxicam (Feldene), sulindac (Clinoril), or tolmetin (Tolectin). You may experience a similar reaction to Bextra.

Bextra should not be used for the treatment of pain after coronary artery bypass surgery (CABG). The use of Bextra in such patients has led to an increased incidence of cardiovascular events, deep surgical infections and wound complications. Talk to your doctor before taking Bextra if you are being treated for pain associated with CABG.

Before taking Bextra, tell your doctor if you

• smoke;

• drink alcohol;

• have an ulcer or bleeding in the stomach;

• have liver disease;
• have kidney disease;

• have asthma;

• have congestive heart failure;

• have fluid retention;

• have heart disease;

• have high blood pressure;

• have a coagulation (bleeding) disorder or are taking an anticoagulant (blood thinner) such as warfarin (Coumadin); or

• are taking a steroid medicine such as prednisone (Deltasone and others), methylprednisolone (Medrol and others), prednisolone (Prelone, Pediapred, and others), and others.

You may not be able to take Bextra, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions, or are taking any of the medicines, listed above.

Bextra is in the FDA pregnancy category C. This means that it is not known whether it will be harmful to an unborn baby. Bextra should not be taken late in pregnancy (the third trimester) because it may affect the formation of the baby's heart. Do not take Bextra without first talking to your doctor if you are pregnant or could become pregnant during treatment. It is not known whether Bextra passes into breast milk. Do not take Bextra without first talking to your doctor if you are breast-feeding a baby. If you are over the age of 65 years, you may be more likely to experience side effects from Bextra. You may require a lower dosage or special monitoring during your therapy.

Seek emergency medical attention.

Symptoms of a Bextra overdose include drowsiness, nausea, vomiting, and stomach pain.

Applies to valdecoxib: oral tablet

Along with its needed effects, valdecoxib (the active ingredient contained in Bextra) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking valdecoxib:

Less common

• Bloating or swelling of face, arms, hands, lower legs, feet
• blood in urine
• bloody, black, or sticky stools
• blurred vision
• chills
• decreased or painful urination
• dizziness
• fever
• muscle aches and pains
• nausea
• nervousness
• pale skin
• pounding in the ears
• rapid weight gain
• severe stomach pain
• tingling of the hands or feet
• trouble breathing with exertion
• unusual bleeding or bruising
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds
• yellow eyes or skin

Incidence not known

• Blistering, peeling, loosening of skin
• constipation
• cracks in the skin
• darkened urine
• difficulty swallowing
• fast heartbeat
• hives
• indigestion
• itching
• itching, puffiness, or swelling of the eyelids or around the eyes, face, lips, or tongue
• joint or muscle pain
• large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs
• loss of appetite
• loss of heat from the body
• nausea
• pains in stomach, side, or abdomen, possibly radiating to the back
• red skin lesions, often with a purple center
• red, irritated eyes
• red, swollen skin
• scaly skin
• shortness of breath
• skin rash
• sores, ulcers, or white spots in mouth or on lips
• tightness in chest
• vomiting
• wheezing
• yellow eyes or skin

Symptoms of overdose

Get emergency help immediately if any of the following symptoms of overdose occur while taking valdecoxib:

• Bloody or black tarry stools
• continuing thirst
• dizziness
• drowsiness
• headache, severe or continuing
• nausea and/or vomiting
• shortness of breath
• stomach pain
• sudden decrease in the amount of urine
• swelling of face, fingers, and/or lower legs
• tightness in chest and/or wheezing
• troubled breathing
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds
• weight gain

Some side effects of valdecoxib may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Acid or sour stomach
• belching
• cough
• diarrhea
• ear congestion
• headache
• heartburn
• indigestion
• sore throat

Less common

• Abdominal fullness
• accidental injury
• back pain
• bloating in the abdomen
• excess gas
• rash
• stuffy or runny nose

Summary of Use during Lactation

Valdecoxib was removed from sale in the United States by the U.S. Food and Drug Administration because of long-term cardiovascular toxicity. Limited information indicates that levels of valdecoxib in breastmilk are low. Because there is little published experience with valdecoxib safety during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.

Drug Levels

Maternal Levels. A review article states that breastmilk levels of valdecoxib are much less than 200 mcg/L based on unpublished studies from the author's laboratory.[1]

Valdecoxib is the active metabolite that is rapidly formed from parecoxib. A single 40 mg dose of parecoxib was given intravenously to 40 mothers at an average of 41.9 hours after delivery. Four milk samples were collected over the next 24 hours. The average infant dosages in breastmilk were 0.24 mcg/kg daily for parecoxib and 1.82 mcg/kg daily for valdecoxib. This was equivalent to 0.63% of the weight-adjusted maternal dose in parecoxib equivalents, mostly excreted as valdecoxib. The half-life of valdecoxib in breastmilk was 8.5 hours.[2]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

A single 40 mg dose of parecoxib, a prodrug of valdecoxib, was given intravenously to 40 mothers at an average of 41.9 hours after delivery. The neonatal adaptive score of the breastfed infants was normal at an average of 21.8 hours after the dose.[2]

Effects on Lactation and Breastmilk

A study compared valdecoxib 20 mg and placebo for their opiate-sparing activity in post-cesarean section pain. All patients received epidural fentanyl and bupivacaine as well as intraspinal morphine for postoperative pain. No difference was observed in breastfeeding success rate between mothers who received valdecoxib (n = 25) and placebo (n = 23).[2]

Alternate Drugs to Consider

Acetaminophen, Flurbiprofen, Ibuprofen, Indomethacin, Naproxen, Piroxicam.

References

1. Hale TW. Medications in breastfeeding mothers of preterm infants. Pediatr Ann. 2003;32(5):337-47. PMID: 12774709

2. Paech MJ, Salman S, Ilett KF et al. Transfer of parecoxib and its primary active metabolite valdecoxib via transitional breastmilk following intravenous parecoxib use after cesarean delivery: A comparison of naive pooled data analysis and nonlinear mixed-effects modeling. Anesth Analg. 2012;114:837-44. PMID: 22344242

3. Carvalho B, Chu L, Fuller A et al. Valdecoxib for postoperative pain management after cesarean delivery: a randomized, double-blind, placebo-controlled study. Anesth Analg. 2006;103:664-70. PMID: 16931678