Fenoprofen

7. DRUG INTERACTIONS See Table 1 for clinically significant drug interactions with fenoprophen. 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 betablockers, 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 CALCIUM 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 CALCIUM 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. 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 CALCIUM may diminish the antihypertensive effect of these drugs.

Monitor blood pressure ( 7 ) ACE Inhibitors and ARBs: Concomitant use with FENOPROFEN CALCIUM 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 can reduce natriuretic effect of furosemide and thiazide diuretics. Monitor patients to assure diuretic efficacy including antihypertensive effects ( 7 ) Digoxin: Concomitant use with FENOPROFEN CALCIUM can increase serum concentration and prolong half-life of digoxin.

Monitor serum digoxin levels ( 7 ) 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.

8.1 Pregnancy Risk Summary Use of NSAIDs, including fenoprofen calcium, can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. Because of these risks, limit dose and duration of fenoprofen calcium use between about 20 and 30 weeks of gestation, and avoid fenoprofen calcium use at about 30 weeks of gestation and later in pregnancy (see Clinical Considerations, Data) Premature Closure of Fetal Ductus Arteriosus Use of NSAIDs, including fenoprofen calcium, at about 30 weeks gestation or later in pregnancy increases the risk of premature closure of the fetal ductus arteriosus.

Oligohydramnios/Neonatal Renal Impairment Use of NSAIDs at about 20 weeks gestation or later in pregnancy has been associated with cases of fetal renal dysfunction leading to oligohydramnios, and in some cases, neonatal renal impairment. Data from observational studies regarding other potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. In animal reproduction studies, embryo-fetal lethality and skeletal abnormalities were noted in offspring of pregnant rabbits following oral administration of fenoprofen during organogenesis at 0.6 times the maximum human daily dose of 3200 mg/day.

However, there were no major malformations noted following oral administration of fenoprofen calcium to pregnant rats and rabbits during organogenesis at exposures up to 0.3 and 0.6 times the maximum human daily dose of 3200 mg/day. Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as fenoprofen, resulted in increased pre- and post-implantation loss. Prostaglandins also have been shown to have an important role in fetal kidney development.

In published animal studies, prostaglandin synthesis inhibitors have been reported to impair kidney development when administered at clinically relevant doses. The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Premature Closure of Fetal…