Felodipine 5 mg Tablet, Extended Release, 500-count — NDC 13668-133-05 (Billing 13668-0133-05)

ADVERSE REACTIONS In controlled studies in the United States and overseas, approximately 3,000 patients were treated with felodipine as either the extended-release or the immediate-release formulation. The most common clinical adverse events reported with felodipine extended-release 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 extended-release, 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 extended-release, 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 extended-release tablets 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 extended-release tablets 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 Extended-Release (N = 861) as Monotherapy without Regard to Causality (Incidence of discontinuations shown in parentheses) 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) 2 (0) 8.8 (2.2) 17.4 (2.5) Asthenia 3.3 (0) 3.9 (0) 3.3 (0) 2.2 (0) Warm Sensation 0 (0) 0 (0) 0.9 (0.2) 1.5 (0) Cardiovascular Palpitation 2.4 (0) 0.4 (0) 1.4 (0.3) 2.5 (0.5) Digestive Nausea 1.5 (0.9) 1.2 (0) 1.7 (0.3) 1 (0.7) Dyspepsia 1.2 (0) 3.9 (0) 0.7 (0) 0.5 (0) Constipation 0.9 (0) 1.2 (0) 0.3 (0) 1.5 (0.2) Nervous Headache 10.2 (0.9) 10.6 (0.4) 11 (1.7) 14.7 (2) Dizziness 2.7 (0.3) 2.7 (0) 3.6 (0.5) 3.7 (0.5) Paresthesia 1.5 (0.3) 1.6 (0) 1.2 (0) 1.2 (0.2) Respiratory Upper Respiratory Infection 1.8 (0) 3.9 (0) 1.9 (0) 0.7 (0) Cough 0.3 (0) 0.8 (0) 1.2 (0) 1.7 (0) Rhinorrhea 0 (0) 1.6 (0) 0.2 (0) 0.2 (0) Sneezing 0 (0) 1.6 (0) 0 (0) 0 (0) Skin Rash 0.9 (0) 2 (0) 0.2 (0) 0.2 (0) Flushing 0.9 (0.3) 3.9 (0) 5.3 (0.7) 6.9 (1.2) * Patients in titration studies may have been exposed to more than one dose level of felodipine extended-release tablets.

Adverse events that occurred in 0.5% up to 1.5% of patients who received felodipine extended-release 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 extended-release 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: Angioede… [Excerpted — this section continues on DailyMed.]

Drug Interactions CYP3A4 Inhibitors Felodipine is metabolized by CYP3A4. Coadministration of CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, erythromycin, grapefruit juice, cimetidine) with felodipine may lead to several-fold increases in the plasma levels of felodipine, either due to an increase in bioavailability or due to a decrease in metabolism. These increases in concentration may lead to increased effects, (lower blood pressure and increased heart rate).

These effects have been observed with coadministration of itraconazole (a potent CYP3A4 inhibitor). Caution should be used when CYP3A4 inhibitors are coadministered with felodipine. A conservative approach to dosing felodipine should be taken.

The following specific interactions have been reported: Itraconazole Coadministration of another extended-release formulation of felodipine with itraconazole resulted in approximately 8-fold increase in the AUC, more than 6-fold increase in the C max , and 2-fold prolongation in the half-life of felodipine. Erythromycin Coadministration of felodipine with erythromycin resulted in approximately 2.5-fold increase in the AUC and C max , and about 2-fold prolongation in the half-life of felodipine. Grapefruit Juice Coadministration of felodipine with grapefruit juice resulted in more than 2-fold increase in the AUC and C max , but no prolongation in the half-life of felodipine.

Cimetidine Coadministration of felodipine with cimetidine (a non-specific CYP-450 inhibitor) resulted in an increase of approximately 50% in the AUC and the C max , of felodipine. Beta-Blocking Agents A pharmacokinetic study of felodipine in conjunction with metoprolol demonstrated no significant effects on the pharmacokinetics of felodipine. The AUC and C max of metoprolol, however, were increased approximately 31 and 38%, respectively.

In controlled clinical trials, however, beta-blockers including metoprolol were concurrently administered with felodipine and were well tolerated. Digoxin When given concomitantly with felodipine extended-release the pharmacokinetics of digoxin in patients with heart failure were not significantly altered. Anticonvulsants In a pharmacokinetic study, maximum plasma concentrations of felodipine were considerably lower in epileptic patients on long-term anticonvulsant therapy (e.g. phenytoin, carbamazepine, or phenobarbital) than in healthy volunteers.

In such patients, the mean area under the felodipine plasma concentration-time curve was also reduced to approximately 6% of that observed in healthy volunteers. Since a clinically significant interaction may be anticipated, alternative antihypertensive therapy should be considered in these patients. Tacrolimus Felodipine may increase the blood concentration of tacrolimus.

When given concomitantly with felodipine, the tacrolimus blood concentration should be followed and the tacrolimus dose may need to be adjusted. Other Concomitant Therapy In healthy subjects there were no clinically significant interactions when felodipine was given concomitantly with indomethacin or spironolactone. Interaction with Food See CLINICAL PHARMACOLOGY: Pharmacokinetics and Metabolism.

PRECAUTIONS General Hypotension Felodipine, like other calcium antagonists, may occasionally precipitate significant hypotension and, rarely, syncope. It may lead to reflex tachycardia which in susceptible individuals may precipitate angina pectoris. (See ADVERSE REACTIONS.) Heart Failure Although acute hemodynamic studies in a small number of patients with NYHA Class II or III heart failure treated with felodipine have not demonstrated negative inotropic effects, safety in patients with heart failure has not been established.

Caution, therefore, should be exercised when using felodipine extended-release in patients with heart failure or compromised ventricular function, particularly in combination with a beta-blocker. 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 extended-release; therefore, a starting dose of 2.5 mg once a day is recommended. These patients should have their blood pressure monitored closely during dosage adjustment of felodipine extended-release.

(See CLINICAL PHARMACOLOGY and DOSAGE AND ADMINISTRATION.) Peripheral Edema Peripheral edema, generally mild and not associated with generalized fluid retention, was the most common adverse event in the clinical trials. The incidence of peripheral edema was both dose and age dependent. Frequency of peripheral edema ranged from about 10% in patients under 50 years of age taking 5 mg daily to about 30% in those over 60 years of age taking 20 mg daily.

This adverse effect generally occurs within 2 to 3 weeks of the initiation of treatment.