Rofecoxib

DEA NFLIS-Drug Category -> Analgesics

Pharmaceuticals

Pharmaceuticals -> Listed in ZINC15

Insoluble

Sparingly soluble in acetone, slightly soluble in methanol and isopropyl acetate, very slightly soluble in ethanol, practically insoluble in octanol, and insoluble in water.

In water, 472 mg/L at 25 °C /Estimated/

FDA approved drugs -> Active ingredient

FDA approved drugs -> Active ingredient

Pharmaceuticals

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P301+P317, P330, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 42 reports by companies from 1 notifications to the ECHA C&L Inventory.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Concurrent use /of rifampin/ with rofecoxib may decrease rofecoxib plasma concentrations by 50%; ... .

Rofecoxib 75 mg per day for 10 days increased plasma methotrexate concentrations by 23% in patients receiving methotrexate 7.5 to 15 mg/week; the effect of recommended doses of rofecoxib in unknown; therefore, monitoring for methotrexate toxicity is recommended.

Concurrent use /of aspirin/ with rofecoxib may increase the risk for gastrointestinal (GI) ulcerations or GI complications.

The administration of rofecoxib with calcium carbonate-, aluminum- or magnesium-containing antacids decreased the area under the plasma concentration-time curve (AUC) by 13% and 8%, respectively, in elderly patients; the peak plasma concentration of rofecoxib was decreased by approximately 20% for both antacids.

For more Interactions (Complete) data for ROFECOXIB (14 total), please visit the HSDB record page.

In clinical studies involving several thousand patients treated for at least 3 months, the rate of serum aminotransferase enzyme elevations above three times the upper limit of the normal range was 1.8% in rofecoxib treated compared to 0.3% in placebo treated patients and 0.1-0.4% in patients receiving other common NSAIDs. Thus, ALT elevations due to rofecoxib were uncommon and usually of minimal clinical significance, resolving even with drug continuation.

/CASE REPORTS/ A 77-year old mildly hypertensive woman with no underlying renal disease who was admitted to the Emergency Department (ED) in a comatose state with fever. The patient had been on low dose enalapril and a potassium rich diet. Five days before admission, rofecoxib, a new selective COX-2 inhibitor nonsteroidal anti-inflammatory drug (NSAID), was added for leg pain. She was found to have severe hyperkalemia and died 90 min after her arrival. A cannot absolutely determine whether the COX-2 inhibitor was the dominant contributor to the development of hyperkalemia or the combination itself, with an intercurrent infection and some degree of dehydration. Physicians should be aware of this possible complication and only prescribe NSAIDs, including the new COX-2 drugs, to the elderly under close monitoring of kidney function and electrolyte tests.

/CASE REPORTS/ Angioedema is a recognised side effect of rofecoxib, a cyclo-oxygenase-2 (COX-2) inhibitor. But death resulting from a hemorrhagic pulmonary edema after its ingestion has not been recorded. The case of a 60 year old man who died from hemorrhagic pulmonary edema in the presence of angioedema after the ingestion of two doses of 12.5 mg of rofecoxib is reported.

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

ROFECOXIB

DILI Positive

Oral

DOI:10.1016/j.drudis.2019.09.022

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ Rofecoxib was not carcinogenic in mice given oral doses up to 30 mg/kg (male) and 60 mg/kg (female) and in male and female rats given oral doses up to 8 mg/kg for two years.

/GENOTOXICITY/ Rofecoxib was not mutagenic in an Ames test or in a V-79 mammalian cell mutagenesis assay, nor clastogenic in a chromosome aberration assay in Chinese hamster ovary (CHO) cells, in an in vitro and an in vivo alkaline elution assay, or in an in vivo chromosomal aberration test in mouse bone marrow.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Rofecoxib did not impair male fertility in rats at oral doses up to 100 mg/kg and rofecoxib had no effect on fertility in female rats at doses up to 30 mg/kg.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Rofecoxib was not teratogenic in rats at doses up to 50 mg/kg/day. There was a slight, non-statistically significant increase in the overall incidence of vertebral malformations only in the rabbit at doses of 50 mg/kg/day.

/LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ Rofecoxib produced peri-implantation and post-implantation losses and reduced embryo/fetal survival in rats and rabbits at oral doses >/=10 and >/=75 mg/kg/day, respectively. These changes are expected with inhibition of prostaglandin synthesis and are not the result of permanent alteration of female reproductive function. There was an increase in the incidence of postnatal pup mortality in rats at >/=5 mg/kg/day. In studies in pregnant rats administered single doses of rofecoxib, there was a treatment-related decrease in the diameter of the ductus arteriosus at all doses used. As with other drugs known to inhibit prostaglandin synthesis.

M - Musculo-skeletal system

QM - Musculo-skeletal system

Rofecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is classified as a nonsteroidal anti-inflammatory drug (NSAID). Unlike celecoxib, rofecoxib lacks a sulfonamide chain and does not require CYP450 enzymes for metabolism. Like other NSAIDs, rofecoxib exhibits anti-inflammatory, analgesic, and antipyretic activity. NSAIDs appear to inhibit prostaglandin synthesis via the inhibition of cyclooxygenase (COX), which are responsible for catalyzing the formation of prostaglandins in the arachidonic acid pathyway. There are at least two isoenzymes, COX-1 and COX-2, that have been identified. Although the exact mechanisms have not been clearly established, NSAIDs exert their anti-inflammatory, analgesic, and antipyretic primarily through the inhibition of COX-2. The inhibition of COX-1 is principally responsible for the negative effects on the GI mucosa. As rofecoxib is selective for COX-2, it may be potentially associated with a decreased risk of certain adverse events, but more data is needed to fully evaulate the drug.

The anti-inflammatory, analgesic, and antipyretic effects of NSAIDs appear to result from the inhibition of prostaglandin synthesis. Although the exact mechanism of action has not been determined, these effects appear to be mediated through the inhibition of the COX-2 isoenzyme at the sites of inflammation with subsequent reduction in the synthesis of certain prostaglandins from their arachidonic acid precursors. Rofecoxib selectively inhibits the cyclooxygenase-2 (COX-2) enzyme, which is important for the mediation of inflammation and pain. Unlike non-selective NSAIDs, rofecoxib does not inhibit platelet aggregation. It also has little to no affinity for COX-1.

Rofecoxib is a nonsteroidal anti-inflammatory drug (NSAID) with anti-inflammatory, analgesic, and antipyretic therapeutic effects. It has been proposed that rofecoxib inhibits the activity of the enzyme cyclooxygenase-2 (COX-2), resulting in a decreased formation of precursors of prostaglandins. Rofecoxib does not inhibit cyclooxygenase-1 (COX-1) isoenzyme in humans at therapeutic concentrations.

17 hours

Approximately 17 hours.

Hepatic. Metabolism of rofecoxib is primarily mediated through reduction by cytosolic enzymes. The principal metabolic products are the cis-dihydro and trans-dihydro derivatives of rofecoxib, which account for nearly 56% of recovered radioactivity in the urine. An additional 8.8% of the dose was recovered as the glucuronide of the hydroxy derivative, a product of oxidative metabolism. The biotransformation of rofecoxib and this metabolite is reversible in humans to a limited extent (< 5%). These metabolites are inactive as COX-1 or COX-2 inhibitors. Cytochrome P450 plays a minor role in metabolism of rofecoxib.

The metabolism of rofecoxib, a potent and selective inhibitor of cyclooxygenase-2, was examined in vitro using human liver subcellular fractions. The biotransformation of rofecoxib was highly dependent on the subcellular fraction and the redox system used. In liver microsomal incubations, NADPH-dependent oxidation of rofecoxib to 5-hydroxyrofecoxib predominated, whereas NADPH-dependent reduction of rofecoxib to the 3,4-dihydrohydroxy acid metabolites predominated in cytosolic incubations. In incubations with S9 fractions, metabolites resulting from both oxidative and reductive pathways were observed. In contrast to microsomes, the oxidation of rofecoxib to 5-hydroxyrofecoxib by S9 fractions followed two pathways, one NADPH-dependent and one NAD+-dependent (non-cytochrome P450), with the latter accounting for about 40% of total activity. The 5-hydroxyrofecoxib thus formed was found to undergo NADPH-dependent reduction ("back reduction") to rofecoxib in incubations with liver cytosolic fractions. In incubations with dialyzed liver cytosol, net hydration of rofecoxib to form 3,4-dihydro-5-hydroxyrofecoxib was observed, whereas the 3,4-dihydrohydroxy acid derivatives were formed when NADPH was present. Although 3,4-dihydro-5-hydroxyrofecoxib could be reduced to the 3,4-dihydrohydroxy acid by cytosol in the presence of NADPH, the former species does not appear to serve as an intermediate in the overall reductive pathway of rofecoxib metabolism. In incubations of greater than 2 h with S9 fractions, net reductive metabolism predominated over oxidative metabolism. These in vitro results are consistent with previous findings on the metabolism of rofecoxib in vivo in human and provide a valuable insight into mechanistic aspects of the complex metabolism of this drug.

Metabolism of rofecoxib is primarily mediated through reduction by cytosolic enzymes. The principal metabolic products are the cis-dihydro and trans-dihydro derivatives of rofecoxib, which account for nearly 56% of recovered radioactivity in the urine. An additional 8.8% of the dose was recovered as the glucuronide of the hydroxy derivative, a product of oxidative metabolism. The biotransformation of rofecoxib and this metabolite is reversible in humans to a limited extent (<5%). Theses metabolites are inactive as COX-1 or COX-2 inhibitors.

Rofecoxib has known human metabolites that include 5-hydroxy-rofecoxib.

The mean oral bioavailability of rofecoxib at therapeutically recommended doses of 12.5, 25, and 50 mg is approximately 93%.

Approximately 72% and 14% of a radioactive rofecoxib dose is eliminated in the urine as metabolites and /in/ feces as unchanged drug, respectively.

Time to peak concentration: Approximately 2 to 3 hours.

At steady state, the apparent volume of distribution is about 91 and 86 L after a 12.5 and 25 mg dose, respectively.

At recommended doses, the mean oral bioavailability is 93%. The peak plasma concentration and area under the plasma concentration-time curve are roughly proportional across the clinical dose range.

For more Absorption, Distribution and Excretion (Complete) data for ROFECOXIB (11 total), please visit the HSDB record page.

Medication: anti-inflammatory

Use (kg) in USA (2002): 13900

Condensation of phenylacetic acid with ethyl bromoacetate in the presence of triethylamine in THF yields ethyl 2-(phenylacetoxy)acetate, which is cyclized to the hydroxyfuranone using potassium tert-butoxide in tert-butanol. The reaction with trifluorosulfonyl anhydride and diisopropylethylamine in CH2Cl2 affords the corresponding trifluorosulfonate, which by reaction with LiBr in hot acetone yields the bromofuranone. The coupling with 4-(methylsulfanyl)phenylboronic acid with Na2CO3 and Pd[(C6H5)3P]4 as catalysts in hot toluene gives 4-[4-(methylsulfanyl)phenyl]-3-phenylfuran-2(5H)-one, which is finally oxidized with 2KHSO5.KHSO4.K2SO4(oxone)

Vioxx

Oral: Tablets: 12.5 mg Vioxx (Merck); 25 mg Vioxx (Merck); 50 mg Vioxx (Merck). Oral Suspension: 12.5 mg/5 mL Vioxx (Merck); 25 mg/5 mL Vioxx (Merck).

/Merck & Co., Inc. announced a voluntary withdrawal of Vioxx (rofecoxib) from the U.S. and worldwide market/ due to safety concerns of an increased risk of cardiovascular events (including heart attack and stroke) in patients on Vioxx. Vioxx is a prescription COX-2 selective, non-steroidal anti-inflammatory drug (NSAID) that was approved by FDA in May 1999 for the relief of the signs and symptoms of osteoarthritis, for the management of acute pain in adults, and for the treatment of menstrual symptoms, and was later approved for the relief of the signs and symptoms of rheumatoid arthritis in adults and children.

Information available in 2004 indicated that Rofecoxib was used in the manufacture of pharmaceutical preparations in the following countries: Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Costa Rica, Croatia, Denmark, Ecuador, El Salvador, Finland, France, Germany, Greece, Guatemala, Honduras, Hong Kong, Hungary, India, Indonesia, Ireland, Israel, Italy, Malaysia, Mexico, Netherlands, New Zealand, Nicaragua, Norway, Panama, Poland, Portugal, Romania, Singapore, Slovenia, South Africa, Spain, Sweden, Switzerland, Thailand, Turkey, United Kingdom, USA, Yugoslavia (1,2)