Fenoprofen

INDICATIONS AND USAGE Fenoprofen calcium is indicated for: • Relief of mild to moderate pain in adults • Relief of the signs and symptoms of rheumatoid arthritis • Relief of the signs and symptoms of osteoarthritis Fenoprofen calcium is a nonsteroidal anti-inflammatory drug indicated for: • Relief of mild to moderate pain in adults. ( 1 ) • Relief of the signs and symptoms of rheumatoid arthritis. ( 1 ) • Relief of the signs and symptoms of osteoarthritis. ( 1 )

DOSAGE AND ADMINISTRATION • Use the lowest effective dosage for shortest duration consistent with individual patient treatment goals ( 2.1 ) • Analgesia: For the treatment of mild to moderate pain, the recommended dosage is 200 mg given orally every 4 to 6 hours, as needed ( 2.1 ) • Rheumatoid Arthritis and Osteoarthritis: For the relief of signs and symptoms of rheumatoid arthritis or osteoarthritis the recommended dose is 400 to 600 mg given orally, 3 or 4 times a day. The dose should be tailored to the needs of the patient and may be increased or decreased depending on the severity of the symptoms. Dosage adjustments may be made after initiation of drug therapy or during exacerbations of the disease. Total daily dosage should not exceed 3,200 mg. 2.1 General Dosing Instructions Carefully consider the potential benefits and risks of fenoprofen calcium and other treatment options before deciding to use fenoprofen. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals. Use lowest effective dosage for the shortest duration consistent with individual patient treatment goals [ see Warnings and Precautions ( 5 ) ]. Fenoprofen calcium may be administered with meals or with milk. Although the total amount absorbed is not affected, peak blood levels are delayed and diminished. Patients with rheumatoid arthritis generally seem to require larger doses of fenoprofen calcium than do those with osteoarthritis. The smallest dose that yields acceptable control should be employed. Although improvement may be seen in a few days in many patients, an additional 2 to 3 weeks may be required to gauge the full benefits of therapy. 2.2 Analgesia For the treatment of mild to moderate pain, the recommended dosage is 200 mg given orally every 4 to 6 hours, as needed. 2.3 Rheumatoid Arthritis and Osteoarthritis For the relief of signs and symptoms of rheumatoid arthritis or osteoarthritis the recommended dose is 400 to 600 mg given orally, 3 or 4 times a day. The dose should be tailored to the needs of the patient and may be increased or decreased depending on the severity of the symptoms. Dosage adjustments may be made after initiation of drug therapy or during exacerbations of the disease. Total daily dosage should not exceed 3,200 mg.

WARNINGS AND PRECAUTIONS • Hepatotoxicity: Inform patients of warning signs and symptoms of hepatotoxicity. Discontinue if abnormal liver tests persist or worsen or if clinical signs and symptoms of liver disease develop ( 5.3 ) • Hypertension: Patients taking some antihypertensive medications may have impaired response to these therapies when taking NSAIDs. Monitor blood pressure ( 5.4 , 7 ) • Heart Failure and Edema: Avoid use of fenoprofen calcium in patients with severe heart failure unless benefits are expected to outweigh risk of worsening heart failure ( 5.5 ) • Renal Toxicity: Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia. Avoid use of fenoprofen calcium in patients with advanced renal disease unless benefits are expected to outweigh risk of worsening renal function ( 5.6 ) • Anaphylactic Reactions: Seek emergency help if an anaphylactic reaction occurs ( 5.7 ) • Exacerbation of Asthma Related to Aspirin Sensitivity: Fenoprofen calcium is contraindicated in patients with aspirin-sensitive asthma. Monitor patients with preexisting asthma (without aspirin sensitivity) ( 5.8 ) • Serious Skin Reactions: Discontinue fenoprofen calcium at first appearance of skin rash or other signs of hypersensitivity ( 5.9 ) • Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Discontinue and evaluate clinically ( 5.10 ) • Fetal Toxicity; Limit use of NSAIDs, including fenoprofen calcium, between about 20 to 30 weeks in pregnancy due to the risk of oligohydramnios/fetal renal dysfunction. Avoid use of NSAIDs in women at about 30 weeks gestation and later in pregnancy due to the risks of oligohydramnios/fetal renal dysfunction and premature closure of the fetal ductus arteriosus ( 5.11 , 8.1 ) • Hematologic Toxicity: Monitor hemoglobin or hematocrit in patients with any signs or symptoms of anemia ( 5.12 , 7 ) 5.1 Cardiovascular Thrombotic Events Clinical trials of several COX-2 selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular (CV) thrombotic events, including myocardial infarction (MI) and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDs. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses. To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events, throughout the entire treatment course, even in the absence of previous CV symptoms. Patients should be informed about the symptoms of serious CV events and the steps to take if they occur. There is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use. The concurrent use of aspirin and an NSAID, such as fenoprofen, increases the risk of serious gastrointestinal (GI) events [ see Warnings and Precautions ( 5.2 ) ]. Status Post Coronary Artery Bypass Graft (CABG) Surgery Two large, controlled clinical trials of a COX-2 selective NSAID for the treatment of pain in the first 10 to 14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the setting of CABG [ see Contraindications ( 4 ) ]. Post-MI Patients Observational studies conducted in the Danish National Registry have demonstrated that patients treated with NSAIDs in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment. In this same cohort, the incidence of death in the first year post-MI was 20 per 100 person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients. Although the absolute rate of death declined somewhat after the first year post-MI, the increased relative risk of death in NSAID users persisted over at least the next four years of follow-up. Avoid the use of fenoprofen calcium in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If fenoprofen calcium is used in patients with a recent MI, monitor patients for signs of cardiac ischemia. 5.2 Gastrointestinal Bleeding, Ulceration, and Perforation NSAIDs, including fenoprofen calcium, cause serious gastrointestinal (GI) adverse events including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, small intestine, or large intestine, which can be fatal. These serious adverse events can occur at any time, with or without warning symptoms, in patients treated with NSAIDs. Only one in five patients who develop a serious upper GI adverse event on NSAID therapy is symptomatic. Upper GI ulcers, gross bleeding, or perforation caused by NSAIDs occurred in approximately 1% of patients treated for 3-6 months, and in about 2% to 4% of patients treated for one year. However, even short-term NSAID therapy is not without risk. Risk Factors for GI Bleeding, Ulceration, and Perforation Patients with a prior history of peptic ulcer disease and/or GI bleeding who used NSAIDs had a greater than 10-fold increased risk for developing a GI bleed compared to patients without these risk factors. Other factors that increase the risk of GI bleeding in patients treated with NSAIDs include longer duration of NSAID therapy; concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors (SSRIs); smoking; use of alcohol; older age; and poor general health status. Most postmarketing reports of fatal GI events occurred in elderly or debilitated patients. Additionally, patients with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding. Strategies to Minimize the GI Risks in NSAID-treated Patients: • Use the lowest effective dosage for the shortest possible duration. • Avoid administration of more than one NSAID at a time. • Avoid use in patients at higher risk unless benefits are expected to outweigh the increased risk of bleeding. For such patients, as well as those with active GI bleeding, consider alternate therapies other than NSAIDs. • Remain alert for signs and symptoms of GI ulceration and bleeding during NSAID therapy. • If a serious GI adverse event is suspected, promptly initiate evaluation and treatment, and discontinue fenoprofen calcium until a serious GI adverse event is ruled out. • In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, monitor patients more closely for evidence of GI bleeding [ see Drug Interactions ( 7 ) ]. 5.3 Hepatotoxicity Elevations of ALT or AST (three or more times the upper limit of normal [ULN]) have been reported in approximately 1% of NSAID-treated patients in clinical trials. In addition, rare, sometimes fatal, cases of severe hepatic injury, including fulminant hepatitis, liver necrosis, and hepatic failure have been reported. Elevations of ALT or AST (less than three times ULN) may occur in up to 15% of patients treated with NSAIDs including fenoprofen. Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, diarrhea, pruritus, jaundice, right upper quadrant tenderness, and “flu-like” symptoms). If clinical signs and symptoms consistent with liver disease develop, or if s

CONTRAINDICATIONS Fenoprofen calcium is contraindicated in the following patients: • Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to fenoprofen or any components of the drug product [ see Warnings and Precautions ( 5.7 , 5.9 ) ] • History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients [ see Warnings and Precautions ( 5.7 , 5.8 ) ] • In the setting of coronary artery bypass graft (CABG) surgery [ see Warnings and Precautions ( 5.1 ) ] • Known hypersensitivity to fenoprofen or any components of the drug product ( 4 ) • History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs ( 4 ) • In the setting of CABG surgery ( 4 )

DRUG INTERACTIONS See Table 1 for clinically significant drug interactions with fenoprofen. Table 1: Clinically Significant Drug Interactions with Fenoprofen Drugs That Interfere with Hemostasis Clinical Impact: • Fenoprofen and anticoagulants such as warfarin have a synergistic effect on bleeding. The concomitant use of fenoprofen and anticoagulants have an increased risk of serious bleeding compared to the use of either drug alone. • Serotonin release by platelets plays an important role in hemostasis. Case-control and cohort epidemiological studies showed that concomitant use of drugs that interfere with serotonin reuptake and an NSAID may potentiate the risk of bleeding more than an NSAID alone. Intervention: Monitor patients with concomitant use of fenoprofen calcium with anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin), selective serotonin reuptake inhibitors (SSRIs), and serotonin norepinephrine reuptake inhibitors (SNRIs) for signs of bleeding [ see Warnings and Precautions ( 5.12 ) ]. Aspirin Clinical Impact: Controlled clinical studies showed that the concomitant use of NSAIDs and analgesic doses of aspirin does not produce any greater therapeutic effect than the use of NSAIDs alone. In a clinical study, the concomitant use of an NSAID and aspirin was associated with a significantly increased incidence of GI adverse reactions as compared to use of the NSAID alone [ see Warnings and Precautions ( 5.2 ) ]. Intervention: Concomitant use of fenoprofen calcium and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding [ see Warnings and Precautions ( 5.12 ) ]. Fenoprofen calcium is not a substitute for low dose aspirin for cardiovascular protection. ACE Inhibitors, Angiotensin Receptor Blockers, and Beta-Blockers Clinical Impact: • NSAIDs may diminish the antihypertensive effect of angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or beta-blockers (including propranolol). • In patients who are elderly, volume-depleted (including those on diuretic therapy), or have renal impairment, co-administration of an NSAID with ACE inhibitors or ARBs may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Intervention: • During concomitant use of fenoprofen calcium and ACE-inhibitors, ARBs, or beta-blockers, monitor blood pressure to ensure that the desired blood pressure is obtained. • During concomitant use of fenoprofen calcium ACE-inhibitors, or ARBs in patients who are elderly, volume-depleted, or have impaired renal function, monitor for signs of worsening renal function [ see Warnings and Precautions ( 5.6 ) ]. • When these drugs are administered concomitantly, patients should be adequately hydrated. Assess renal function at the beginning of the concomitant treatment and periodically thereafter. Diuretics Clinical Impact: Clinical studies, as well as post-marketing observations, showed that NSAIDs reduced the natriuretic effect of loop diuretics (e.g., furosemide) and thiazide diuretics in some patients. This effect has been attributed to the NSAID inhibition of renal prostaglandin synthesis. Intervention: During concomitant use of fenoprofen calcium with diuretics, observe patients for signs of worsening renal function, in addition to assuring diuretic efficacy including antihypertensive effects [ see Warnings and Precautions ( 5.6 ) ]. Digoxin Clinical Impact: The concomitant use of fenoprofen with digoxin has been reported to increase the serum concentration and prolong the half-life of digoxin. Intervention: During concomitant use of fenoprofen calcium and digoxin, monitor serum digoxin levels. Lithium Clinical Impact: NSAIDs have produced elevations in plasma lithium levels and reductions in renal lithium clearance. The mean minimum lithium concentration increased 15%, and the renal clearance decreased by approximately 20%. This effect has been attributed to NSAID inhibition of renal prostaglandin synthesis. Intervention: During concomitant use of fenoprofen calcium and lithium, monitor patients for signs of lithium toxicity. Methotrexate Clinical Impact: Concomitant use of NSAIDs and methotrexate may increase the risk for methotrexate toxicity (e.g., neutropenia, thrombocytopenia, renal dysfunction). Intervention: During concomitant use of fenoprofen and methotrexate, monitor patients for methotrexate toxicity. Cyclosporine Clinical Impact: Concomitant use of fenoprofen calcium and cyclosporine may increase cyclosporine’s nephrotoxicity. Intervention: During concomitant use of fenoprofen calcium and cyclosporine, monitor patients for signs of worsening renal function. NSAIDs and Salicylates Clinical Impact: Concomitant use of fenoprofen with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy [ see Warnings and Precautions ( 5.2 ) ]. Intervention: The concomitant use of fenoprofen with other NSAIDs or salicylates is not recommended. Pemetrexed Clinical Impact: Concomitant use of fenoprofen calcium and pemetrexed may increase the risk of pemetrexed-associated myelosuppression, renal, and GI toxicity (see the pemetrexed prescribing information). Intervention: During concomitant use of fenoprofen and pemetrexed, in patients with renal impairment whose creatinine clearance ranges from 45 to 79 mL/min, monitor for myelosuppression, renal and GI toxicity. NSAIDs with short elimination half-lives (e.g., diclofenac, indomethacin) should be avoided for a period of two days before, the day of, and two days following administration of pemetrexed. In the absence of data regarding potential interaction between pemetrexed and NSAIDs with longer half-lives (e.g., meloxicam, nabumetone), patients taking these NSAIDs should interrupt dosing for at least five days before, the day of, and two days following pemetrexed administration. Phenobarbital Clinical Impact: Chronic administration of phenobarbital, a known enzyme inducer, may be associated with a decrease in the plasma half-life of fenoprofen. Intervention: When phenobarbital is added to or withdrawn from treatment, dosage adjustment of fenoprofen calcium may be required. Hydantoins, sulfonamides, or sulfonylureas Clinical Impact: In vitro studies have shown that fenoprofen, because of its affinity for albumin, may displace from their binding sites other drugs that are also albumin bound, and this may lead to drug interactions. Theoretically, fenoprofen could likewise be displaced. Intervention: Patients receiving hydantoins, sulfonamides, or sulfonylureas should be observed for increased activity of these drugs and, therefore, signs of toxicity from these drugs. Drug/laboratory Test Interactions Amerlex-M kit assay values of total and free triiodothyronine in patients receiving fenoprofen calcium have been reported as falsely elevated on the basis of a chemical cross-reaction that directly interferes with the assay. Thyroid-stimulating hormone, total thyroxine, and thyrotropin-releasing hormone response are not affected. Thus, results of the Amerlex-M kit assay should be interpreted with caution in these patients. • Drugs that Interfere with Hemostasis (e.g. warfarin, aspirin, SSRIs/SNRIs): Monitor patients for bleeding who are concomitantly taking fenoprofen calcium with drugs that interfere with hemostasis. Concomitant use of fenoprofen calcium and analgesic doses of aspirin is not generally recommended ( 7 ) • ACE Inhibitors, Angiotensin Receptor Blockers (ARB), or Beta-Blockers : Concomitant use with fenoprofen may diminish the antihypertensive effect of these drugs. Monitor blood pressure ( 7 ) • ACE Inhibitors and ARBs: Concomitant use with fenoprofen in elderly, volume depleted, or those with renal impairment may result in deterioration of renal function. In such high risk patients, monitor for signs of worsening renal function ( 7 ) • Diuretics: NSAIDs

ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: •Cardiovascular Thrombotic Events [ see Warnings and Precautions ( 5.1 ) ] •GI Bleeding, Ulceration and Perforation [ see Warnings and Precautions ( 5.2 ) ] •Hepatotoxicity [ see Warnings and Precautions ( 5.3 ) ] •Hypertension [ see Warnings and Precautions ( 5.4 ) ] •Heart Failure and Edema [ see Warnings and Precautions ( 5.5 ) ] •Renal Toxicity and Hyperkalemia [ see Warnings and Precautions ( 5.6 ) ] •Anaphylactic Reactions [ see Warnings and Precautions ( 5.7 ) ] •Serious Skin Reactions [ see Warnings and Precautions ( 5.9 ) ] •Hematologic Toxicity [ see Warnings and Precautions ( 5.12 ) ] Most common adverse reactions (incidence ≥ 5%) are Dyspepsia, headache, somnolence, nausea, dizziness, constipation, nervousness, asthenia, and peripheral edema. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Rising Pharma Holdings, Inc. at 1-844-874-7464 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. During clinical studies for rheumatoid arthritis, osteoarthritis, or mild to moderate pain and studies of pharmacokinetics, complaints were compiled from a checklist of potential adverse reactions, and the following data emerged. These encompass observations in 6,786 patients, including 188 observed for at least 52 weeks. For comparison, data are also presented from complaints received from the 266 patients who received placebo in these same trials. During short-term studies for analgesia, the incidence of adverse reactions was markedly lower than that seen in longer-term studies. Adverse Drug Reactions Reported in >1% of Patients During Clinical Trials Digestive System — During clinical trials with fenoprofen calcium, the most common adverse reactions were gastrointestinal in nature and occurred in 20.8% of patients receiving fenoprofen calcium as compared to 16.9% of patients receiving placebo. In descending order of frequency, these reactions included dyspepsia (10.3% fenoprofen calcium vs. 2.3% placebo), nausea (7.7% vs. 7.1%), constipation (7% vs. 1.5%), vomiting (2.6% vs. 1.9%), abdominal pain (2% vs. 1.1%), and diarrhea (1.8% vs. 4.1%). The drug was discontinued because of adverse gastrointestinal reactions in less than 2% of patients during premarketing studies. Nervous System — The most frequent adverse neurologic reactions were headache (8.7% vs. 7.5%) and somnolence (8.5% vs. 6.4%). Dizziness (6.5% vs. 5.6%), tremor (2.2% vs. 0.4%), and confusion (1.4% vs. none) were noted less frequently. Fenoprofen calcium was discontinued in less than 0.5% of patients because of these side effects during premarketing studies. Skin and Appendages — Increased sweating (4.6% vs. 0.4%), pruritus (4.2% vs. 0.8%), and rash (3.7% vs. 0.4%) were reported. Fenoprofen calcium was discontinued in about 1% of patients because of an adverse effect related to the skin during premarketing studies. Special Senses — Tinnitus (4.5% vs. 0.4%), blurred vision (2.2% vs. none), and decreased hearing (1.6% vs. none) were reported. Fenoprofen calcium was discontinued in less than 0.5% of patients because of adverse effects related to the special senses during premarketing studies. Cardiovascular — Palpitations (2.5% vs. 0.4%). Fenoprofen calcium was discontinued in about 0.5% of patients because of adverse cardiovascular reactions during premarketing studies. Miscellaneous — Nervousness (5.7% vs. 1.5%), asthenia (5.4% vs. 0.4%), peripheral edema (5.0% vs. 0.4%), dyspnea (2.8% vs. none), fatigue (1.7% vs. 1.5%), upper respiratory infection (1.5% vs. 5.6%), and nasopharyngitis (1.2% vs. none). Adverse Drug Reactions Reported in <1% of Patients During Clinical Trials Digestive System —Gastritis, peptic ulcer with/without perforation, gastrointestinal hemorrhage, anorexia, flatulence, dry mouth, and blood in the stool. Increases in alkaline phosphatase, LDH, SGOT, jaundice, and cholestatic hepatitis, aphthous ulcerations of the buccal mucosa, metallic taste, and pancreatitis. Cardiovascular —Atrial fibrillation, pulmonary edema, electrocardiographic changes, and supraventricular tachycardia. Genitourinary Tract —Renal failure, dysuria, cystitis, hematuria, oliguria, azotemia, anuria, interstitial nephritis, nephrosis, and papillary necrosis. Hypersensitivity —Angioedema (angioneurotic edema). Hematologic —Purpura, bruising, hemorrhage, thrombocytopenia, hemolytic anemia, aplastic anemia, agranulocytosis, and pancytopenia. Nervous System —Depression, disorientation, seizures, and trigeminal neuralgia. Special Senses —Burning tongue, diplopia, and optic neuritis. Skin and Appendages —Exfoliative dermatitis, toxic epidermal necrolysis, Stevens-Johnson syndrome, and alopecia. Miscellaneous —Anaphylaxis, urticaria, malaise, insomnia, tachycardia, personality change, lymphadenopathy, mastodynia, and fever. 6.2 Postmarketing Experience The following adverse reactions have been identified during the post-approval use of fenoprofen calcium. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Skin and Appendages — Alopecia, bruising, desquamation, erythema, photosensitivity, sweat, angioedema, toxic epidermal necrosis, erythema multiforme, exfoliative dermatitis, onycholysis, Stevens-Johnson Syndrome, fixed drug eruption (FDE), urticaria, vesiculobullous reaction.

12. CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Fenoprofen has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of fenoprofen calcium, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Fenoprofen is a potent inhibitor of prostaglandin synthesis in vitro . Fenoprofen concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because fenoprofen is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. 12.3 Pharmacokinetics Absorption Under fasting conditions, fenoprofen is rapidly absorbed, and peak plasma levels of 50 mcg/L are achieved within 2 hours after oral administration of 600 mg doses. Good dose proportionality was observed between 200 and 600 mg doses in fasting male volunteers. Distribution Fenoprofen is highly bound (99%) to albumin. Elimination Metabolism The plasma half-life is approximately 3 hours. Excretion About 90% of a single oral dose is eliminated within 24 hours as fenoprofen glucuronide and 4'-hydroxyfenoprofen glucuronide, the major urinary metabolites of fenoprofen. Specific Populations Geriatrics Peak plasma levels of fenoprofen in normal elderly volunteers were similar to those observed in normal young volunteers. Elderly volunteers had a mean plasma clearance of 2.2 L/hour while plasma clearance of fenoprofen in normal young volunteers ranged from 3 to 3.5 L/hour. The overall elimination rate constant, plasma half-life and ratio of renal to nonrenal clearance of fenoprofen was the same in elderly and young volunteers. The 30 to 60% decrease in plasma clearance is due to a decrease in the volume of distribution in the body. Drug Interaction Studies Aspirin: When NSAIDs were administered with aspirin, the protein binding of NSAIDs were reduced, although the clearance of free NSAID was not altered. The clinical significance of this interaction is not known. See Table 1 for clinically significant drug interactions of NSAIDs with aspirin [ see Drug Interactions (7) ]. Antacid: The concomitant administration of antacid (containing both aluminum and magnesium hydroxide) does not interfere with absorption of fenoprofen.