FELDENE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for FELDENE (FELDENE).
Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis, thereby decreasing inflammation, pain, and fever.
| Metabolism | Primarily hepatic via cytochrome P450 (CYP) 2C9, with minor contribution from CYP3A4. Undergoes extensive oxidative metabolism and glucuronidation. |
| Excretion | Approximately 60-70% of a dose is excreted in urine as unchanged drug and metabolites, with about 30-40% eliminated in feces via biliary secretion. |
| Half-life | Terminal elimination half-life is approximately 50 hours (range 30-86 hours), allowing once-daily dosing. The long half-life results from enterohepatic recirculation. |
| Protein binding | Approximately 99% bound to albumin. |
| Volume of Distribution | Apparent volume of distribution is approximately 0.15 L/kg (range 0.1-0.2 L/kg), indicating limited extravascular distribution. |
| Bioavailability | Oral: nearly complete (approximately 100%) with minimal first-pass metabolism. |
| Onset of Action | Oral: analgesic effect begins within 1-2 hours; anti-inflammatory effect may require several days of continuous dosing. |
| Duration of Action | Oral: analgesic duration is 12-24 hours; anti-inflammatory effect persists for up to 24 hours with once-daily dosing due to long half-life. |
20 mg orally once daily, or 10 mg orally twice daily. Maximum daily dose: 20 mg.
| Dosage form | CAPSULE |
| Renal impairment | Contraindicated in patients with GFR <30 mL/min. For GFR 30-60 mL/min, reduce dose to 10 mg once daily. Use with caution and monitor renal function. |
| Liver impairment | Contraindicated in Child-Pugh class C (severe hepatic impairment). For Child-Pugh class A or B, reduce dose to 10 mg once daily. Monitor hepatic function. |
| Pediatric use | Not recommended for pediatric patients <14 years of age. For adolescents (≥14 years), dose as per adult guidelines. |
| Geriatric use | Initiate at 10 mg once daily. Use the lowest effective dose due to increased risk of GI bleeding and renal impairment. Monitor renal function and electrolytes. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for FELDENE (FELDENE).
| Breastfeeding | Excreted in breast milk; M/P ratio unknown. Use with caution, especially in prolonged use, due to potential adverse effects in infant (e.g., renal impairment, gastrointestinal effects). |
| Teratogenic Risk | Pregnancy Category C (1st and 2nd trimesters), Category D (3rd trimester). Avoid in 3rd trimester due to risk of premature closure of ductus arteriosus and oligohydramnios. Use only if potential benefit justifies risk to fetus. |
| Fetal Monitoring |
■ FDA Black Box Warning
NSAIDs cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may increase with duration of use. Patients with cardiovascular disease or risk factors for cardiovascular disease may be at greater risk. FELDENE is contraindicated for the treatment of perioperative pain in the setting of coronary artery bypass graft (CABG) surgery.
| Serious Effects |
History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs. Perioperative pain in setting of CABG. Uncontrolled hypertension, history of myocardial infarction or stroke. Active gastrointestinal bleeding or peptic ulcer disease. Severe heart failure. Advanced renal disease. Known hypersensitivity to piroxicam or any component of the formulation. Third trimester of pregnancy. Caution with concomitant use of anticoagulants or antiplatelet drugs.
| Precautions | Cardiovascular risk: increased risk of serious cardiovascular thrombotic events. Gastrointestinal risk: increased risk of serious GI adverse events including bleeding, ulceration, and perforation. Renal toxicity: monitor renal function in patients with preexisting renal disease, heart failure, liver dysfunction, or in elderly. Hepatic effects: rare but serious liver injury. Anaphylactoid reactions. Fluid retention and edema. Hematologic effects: anemia. Photosensitivity. Masking of signs of infection. |
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| Monitor maternal renal function, blood pressure, and signs of bleeding. In fetus, monitor amniotic fluid volume (ultrasound) if used for prolonged periods in 2nd/3rd trimester. Monitor for ductus arteriosus constriction if used near term. |
| Fertility Effects | May impair fertility in women due to reversible inhibition of ovulation (by interfering with prostaglandin synthesis). Effects are reversible upon discontinuation. |