FELODIPINE

Felodipine, USP is a calcium antagonist (calcium channel blocker). Felodipine, USP is a dihydropyridine derivative that is chemically described as ± ethyl methyl 4-(2,3-dichlorophenyl) -1,4-dihydro-2, 6-dimethyl-3, 5- pyridinedicarboxylate. Its empirical formula is C 18 H 19 Cl 2 NO 4 and its structural formula is: Felodipine, USP is a slightly yellowish, crystalline powder with a molecular weight of 384.26. It is insoluble in water and is freely soluble in dichloromethane and ethanol. Felodipine, USP is a racemic mixture. Felodipine Extended-release Tablets, USP provide extended release of felodipine. They are available as tablets containing 2.5 mg, 5 mg, or 10 mg of felodipine for oral administration. Inactive ingredients for core tablets are: anhydrous lactose, butylated hydroxyanisole, butylated hydroxytoluene, colloidal silicon dioxide, hypromellose, polyoxyl 40 hydrogenated castor oil, microcrystalline cellulose, povidone K30 and sodium stearyl fumarate. Film coating materials of 2.5mg: ferrosoferric oxide, hypromellose, iron oxide red, iron oxide yellow, maltodextrin, medium chain triglycerides, polydextrose, talc and titanium dioxide. Film coating materials of 5mg: ferrosoferric oxide, hypromellose, iron oxide red, iron oxide yellow, maltodextrin, medium chain triglycerides, polydextrose, talc and titanium dioxide. Film coating materials of 10mg: ferrosoferric oxide, hypromellose, iron oxide red, iron oxide yellow, maltodextrin, medium chain triglycerides, polydextrose, talc and titanium dioxide. Chemical Structure

The recommended starting dose is 5 mg once a day. Depending on the patient's response, the dosage can be decreased to 2.5 mg or increased to 10 mg once a day. These adjustments should occur generally at intervals of not less than 2 weeks. The recommended dosage range is 2.5–10 mg once daily. In clinical trials, doses above 10 mg daily showed an increased blood pressure response but a large increase in the rate of peripheral edema and other vasodilatory adverse events (see ADVERSE REACTIONS ). Modification of the recommended dosage is usually not required in patients with renal impairment. Felodipine should regularly be taken either without food or with a light meal (see CLINICAL PHARMACOLOGY, Pharmacokinetics and Metabolism ). Felodipine should be swallowed whole and not crushed or chewed. Geriatric Use —Patients over 65 years of age are likely to develop higher plasma concentrations of felodipine (see CLINICAL PHARMACOLOGY ). In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range (2.5 mg daily). Elderly patients should have their blood pressure closely monitored during any dosage adjustment. Patients with Impaired Liver Function —Patients with impaired liver function may have elevated plasma concentrations of felodipine and may respond to lower doses of Felodipine; therefore, patients should have their blood pressure monitored closely during dosage adjustment of Felodipine (see CLINICAL PHARMACOLOGY ).

Felodipine is contraindicated in patients who are hypersensitive to this product.

In controlled studies in the United States and overseas, approximately 3000 patients were treated with felodipine as either the extended-release or the immediate-release formulation. The most common clinical adverse events reported with Felodipine administered as monotherapy at the recommended dosage range of 2.5 mg to 10 mg once a day were peripheral edema and headache. Peripheral edema was generally mild, but it was age and dose related and resulted in discontinuation of therapy in about 3% of the enrolled patients. Discontinuation of therapy due to any clinical adverse event occurred in about 6% of the patients receiving Felodipine, principally for peripheral edema, headache, or flushing. Adverse events that occurred with an incidence of 1.5% or greater at any of the recommended doses of 2.5 mg to 10 mg once a day (Felodipine, N = 861; Placebo, N = 334), without regard to causality, are compared to placebo and are listed by dose in the table below. These events are reported from controlled clinical trials with patients who were randomized to a fixed dose of Felodipine or titrated from an initial dose of 2.5 mg or 5 mg once a day. A dose of 20 mg once a day has been evaluated in some clinical studies. Although the antihypertensive effect of Felodipine is increased at 20 mg once a day, there is a disproportionate increase in adverse events, especially those associated with vasodilatory effects (see DOSAGE AND ADMINISTRATION ). Percent of Patients with Adverse Events in Controlled Trials* of Felodipine (N = 861) as Monotherapy without Regard to Causality (Incidence of discontinuations shown in parentheses) * Patients in titration studies may have been exposed to more than one dose level of Felodipine. Body System Adverse Events Placebo N = 334 2.5 mg N = 255 5 mg N = 581 10 mg N = 408 Body as a Whole Peripheral Edema 3.3 (0.0) 2.0 (0.0) 8.8 (2.2) 17.4 (2.5) Asthenia 3.3 (0.0) 3.9 (0.0) 3.3 (0.0) 2.2 (0.0) Warm Sensation 0.0 (0.0) 0.0 (0.0) 0.9 (0.2) 1.5 (0.0) Cardiovascular Palpitation 2.4 (0.0) 0.4 (0.0) 1.4 (0.3) 2.5 (0.5) Digestive Nausea 1.5 (0.9) 1.2 (0.0) 1.7 (0.3) 1.0 (0.7) Dyspepsia 1.2 (0.0) 3.9 (0.0) 0.7 (0.0) 0.5 (0.0) Constipation 0.9 (0.0) 1.2 (0.0) 0.3 (0.0) 1.5 (0.2) Nervous Headache 10.2 (0.9) 10.6 (0.4) 11.0 (1.7) 14.7 (2.0) Dizziness 2.7 (0.3) 2.7 (0.0) 3.6 (0.5) 3.7 (0.5) Paresthesia 1.5 (0.3) 1.6 (0.0) 1.2 (0.0) 1.2 (0.2) Respiratory Upper Respiratory Infection Cough 0.3 (0.0) 0.8 (0.0) 1.2 (0.0) 1.7 (0.0) Rhinorrhea 0.0 (0.0) 1.6 (0.0) 0.2 (0.0) 0.2 (0.0) Sneezing 0.0 (0.0) 1.6 (0.0) 0.0 (0.0) 0.0 (0.0) Skin Rash 0.9 (0.0) 2.0 (0.0) 0.2 (0.0) 0.2 (0.0) Flushing 0.9 (0.3) 3.9 (0.0) 5.3 (0.7) 6.9 (1.2) Adverse events that occurred in 0.5 up to 1.5% of patients who received Felodipine in all controlled clinical trials at the recommended dosage range of 2.5 mg to 10 mg once a day, and serious adverse events that occurred at a lower rate, or events reported during marketing experience (those lower rate events are in italics) are listed below. These events are listed in order of decreasing severity within each category, and the relationship of these events to administration of Felodipine is uncertain: Body as a Whole: Chest pain, facial edema, flu-like illness; Cardiovascular: Myocardial infarction, hypotension, syncope, angina pectoris , arrhythmia , tachycardia, premature beats; Digestive: Abdominal pain, diarrhea, vomiting, dry mouth, flatulence, acid regurgitation; Endocrine : Gynecomastia; Hematologic : Anemia ; Metabolic : ALT (SGPT) increased; Musculoskeletal : Arthralgia, back pain, leg pain, foot pain, muscle cramps, myalgia, arm pain, knee pain, hip pain; Nervous/Psychiatric : Insomnia, depression, anxiety disorders, irritability, nervousness, somnolence, decreased libido; Respiratory : Dyspnea, pharyngitis, bronchitis, influenza, sinusitis, epistaxis, respiratory infection; Skin : Angioedema , contusion, erythema, urticaria, leukocytoclastic vasculitis ; Special Senses : Visual disturbances; Urogenital : Impotence, urinary frequency, urinary urgency, dysuria, polyuria. Gingival Hyperplasia : Gingival hyperplasia, usually mild, occurred in < 0.5% of patients in controlled studies. This condition may be avoided or may regress with improved dental hygiene. (See PRECAUTIONS: Information for Patients. ) Clinical Laboratory Test Findings Serum Electrolytes — No significant effects on serum electrolytes were observed during short- and long-term therapy (see CLINICAL PHARMACOLOGY: Renal/Endocrine Effects ). Serum Glucose — No significant effects on fasting serum glucose were observed in patients treated with Felodipine in the U.S. controlled study. Liver Enzymes —1 of 2 episodes of elevated serum transaminases decreased once drug was discontinued in clinical studies; no follow-up was available for the other patient.