Fluvastatin ER Tablets

Hypersensitivity to any Component of This Medication

Fluvastatin sodium extended-release tablets are contraindicated in patients with hypersensitivity to any component of this medication.

Active Liver Disease

Fluvastatin sodium extended-release tablets are contraindicated in patients with active liver disease or unexplained, persistent elevations in serum transaminases [see Warnings and Precautions (5.2)].

Pregnancy

Fluvastatin sodium extended-release tablets are contraindicated in women who are pregnant or may become pregnant. Serum cholesterol and triglycerides increase during normal pregnancy, and cholesterol or cholesterol derivatives are essential for fetal development. Fluvastatin sodium extended-release tablets may cause fetal harm when administered to pregnant women. Atherosclerosis is a chronic process and the discontinuation of lipid-lowering drugs during pregnancy should have little impact on the outcome of long-term therapy of primary hypercholesterolemia.

Fluvastatin sodium extended-release tablets should be administered to women of childbearing age only when such patients are highly unlikely to conceive and have been informed of the potential hazards. If the patient becomes pregnant while taking this drug, fluvastatin sodium extended-release tablets should be discontinued and the patient should be apprised of the potential hazard to the fetus [see Use in Specific Populations (8.1)].

Nursing Mothers

Fluvastatin is secreted into the breast milk of animals and because HMG-CoA reductase inhibitors have the potential to cause serious adverse reactions in nursing infants, women who require treatment with fluvastatin sodium extended-release tablets should be advised not to breastfeed their infants [see Use in Specific Populations (8.3)].

Pregnancy

Pregnancy Category X

Fluvastatin sodium extended-release tablets are contraindicated in women who are or may become pregnant [see Contraindications (4)].

Lipid lowering drugs are contraindicated during pregnancy, because cholesterol and cholesterol derivatives are needed for normal fetal development. Serum cholesterol and triglycerides increase during normal pregnancy. Atherosclerosis is a chronic process, and discontinuation of lipid-lowering drugs during pregnancy should have little impact on long-term outcomes of primary hypercholesterolemia therapy.

There are no adequate and well-controlled studies of use with fluvastatin sodium extended-release tablets during pregnancy. Rare reports of congenital anomalies have been received following intrauterine exposure to other statins. In a review2 of about 100 prospectively followed pregnancies in women exposed to other statins, the incidences of congenital anomalies, spontaneous abortions, and fetal deaths/stillbirths did not exceed the rate expected in the general population. The number of cases is adequate only to exclude a 3 to 4 fold increase in congenital anomalies over background incidence. In 89% of prospectively followed pregnancies, drug treatment was initiated prior to pregnancy and was discontinued at some point in the first trimester when pregnancy was identified.

Teratology studies with fluvastatin in rats and rabbits showed maternal toxicity at high dose levels, but there was no evidence of embryotoxic or teratogenic potential [see Nonclinical Toxicology (13)].

Fluvastatin sodium extended-release tablets should be administered to women of child-bearing potential only when such patients are highly unlikely to conceive and have been informed of the potential hazards. If a woman becomes pregnant while taking fluvastatin sodium extended-release tablets, the drug should be discontinued and the patient advised again as to the potential hazards to the fetus.

Nursing Mothers

Based on animal data, fluvastatin is present in breast milk in a 2:1 ratio (milk:plasma). Because of the potential for serious adverse reactions in nursing infants, nursing women should not take fluvastatin sodium extended-release tablets [see Contraindications (4)].

Pediatric Use

The safety and efficacy of fluvastatin sodium extended-release tablets in children and adolescent patients 9 to 16 years of age with heterozygous familial hypercholesterolemia have been evaluated in open-label, uncontrolled clinical trials for a duration of two years. The most common adverse events observed were influenza and infections. In these limited uncontrolled studies, there was no detectable effect on growth or sexual maturation in the adolescent boys or on menstrual cycle length in girls [see Clinical Studies (14.2), Adverse Reactions (6.3) and Dosage and Administration (2.2)]. Adolescent females should be counseled on appropriate contraceptive methods while on fluvastatin sodium therapy [see Contraindications (4)].

Geriatric Use

Fluvastatin exposures were not significantly different between the nonelderly and elderly populations (age ≥ 65 years) [see Clinical Pharmacology (12.3)]. Since advanced age (≥ 65 years) is a predisposing factor for myopathy, fluvastatin sodium extended-release tablets should be prescribed with caution in the elderly.

Hepatic Impairment

Fluvastatin sodium extended-release tablets are contraindicated in patients with active liver disease or unexplained, persistent elevations in serum transaminases [see Clinical Pharmacology (12.3)].

Renal Impairment

Dose adjustments for mild to moderate renal impairment are not necessary. Fluvastatin has not been studied at doses greater than 40 mg in patients with severe renal impairment; therefore caution should be exercised when treating such patients at higher doses [see Clinical Pharmacology (12.3)].

To date, there has been limited experience with overdosage of fluvastatin. If an overdose occurs, it should be treated symptomatically with laboratory monitoring and supportive measures should be instituted as required. The dialyzability of fluvastatin sodium and of its metabolites in humans is not known at present [see Warnings and Precautions (5)].

In the pediatric population, there have been reports of overdosage with fluvastatin sodium in children including a 2-year-old and the other 3 years of age, either of whom may have possibly ingested fluvastatin sodium. The maximum amount of fluvastatin sodium that could have been ingested was 80 mg (4 x 20 mg capsules). Vomiting was induced by ipecac in both children and no capsules were noted in their emesis. Neither child experienced any adverse symptoms and both recovered from the incident without problems.

In the postmarketing experience there have been reports of accidental ingestion of fluvastatin capsules in infants up to 3 years of age. In one case, increased serum CPK values were noted. There have been reports of intentional overdose in adolescents with the development of hepatic enzyme elevations, convulsions and gastroenteritis/vomiting/diarrhea. One case of intentional overdose as suicide attempt in a 15-year-old female reported ingestion of 2,800 mg fluvastatin sodium extended-release tablets with hepatic enzyme elevation.

Mechanism of Action

Fluvastatin sodium is a competitive inhibitor of HMG-CoA reductase, the rate limiting enzyme that converts 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) to mevalonate, a precursor of sterols, including cholesterol. The inhibition of cholesterol biosynthesis reduces the cholesterol in hepatic cells, which stimulates the synthesis of LDL receptors and thereby increases the uptake of LDL particles. The end result of these biochemical processes is a reduction of the plasma cholesterol concentration.

Pharmacokinetics

Absorption:

Following oral administration of the capsule, fluvastatin reaches peak concentrations in less than 1 hour. The absolute bioavailability is 24% (range 9% to 50%) after administration of a 10 mg dose.

At steady state, administration of fluvastatin with the evening meal results in a 50% decrease in Cmax, an 11% decrease in AUC, and a more than two-fold increase in tmax as compared to administration 4 hours after the evening meal. No significant differences in the lipid-lowering effects were observed between the two administrations. After single or multiple doses above 20 mg, fluvastatin exhibits saturable first-pass metabolism resulting in more than dose proportional plasma fluvastatin concentrations.

Fluvastatin administered as fluvastatin sodium extended-release tablets, 80 mg reaches peak concentration in approximately 3 hours under fasting conditions, after a low-fat meal, or 2.5 hours after a low-fat meal. The mean relative bioavailability of the extended-release tablet is approximately 29% (range: 9% to 66%) compared to that of the fluvastatin immediate-release capsule administered under fasting conditions. Administration of a high-fat meal delayed the absorption (Tmax: 6h) and increased the bioavailability of the extended-release tablet by approximately 50%. However, the maximum concentration of fluvastatin sodium extended-release tablets seen after a high-fat meal is less than the peak concentration following a single dose or twice daily dose of the 40 mg fluvastatin capsule.

Distribution:

Fluvastatin is 98% bound to plasma proteins. The mean volume of distribution (VDss) is estimated at 0.35 L/kg. At therapeutic concentrations, the protein binding of fluvastatin is not affected by warfarin, salicylic acid and glyburide.

Metabolism:

Fluvastatin is metabolized in the liver, primarily via hydroxylation of the indole ring at the 5 and 6 positions. N-dealkylation and beta-oxidation of the side-chain also occurs. The hydroxy metabolites have some pharmacologic activity, but do not circulate in the blood. Fluvastatin has two enantiomers. Both enantiomers of fluvastatin are metabolized in a similar manner.

In vitro data indicate that fluvastatin metabolism involves multiple Cytochrome P450 (CYP) isozymes. CYP2C9 isoenzyme is primarily involved in the metabolism of fluvastatin (approximately 75%), while CYP2C8 and CYP3A4 isoenzymes are involved to a much less extent, i.e., approximately 5% and approximately 20%, respectively.

Excretion:

Following oral administration, fluvastatin is primarily (about 90%) excreted in the feces as metabolites, with less than 2% present as unchanged drug. Approximately 5% of a radiolabeled oral dose were recovered in urine. The elimination half-life (t1/2) of fluvastatin is approximately 3 hours.

Specific Populations

Renal Impairment:

In patients with moderate to severe renal impairment (CLCr 10 to 40 mL/min), AUC and Cmax increased approximately 1.2 fold after administration of a single dose of 40 mg fluvastatin compared to healthy volunteers. In patients with end-stage renal disease on hemodialysis, the AUC increased by approximately 1.5 fold. Fluvastatin sodium extended-release tablets were not evaluated in patients with renal impairment. However, systemic exposures after administration of fluvastatin sodium extended-release tablets are lower than after the 40 mg immediate release capsule.

Hepatic Impairment:

In patients with hepatic impairment due to liver cirrhosis, fluvastatin AUC and Cmax increased approximately 2.5 fold compared to healthy subjects after administration of a single 40 mg dose. The enantiomer ratios of the two isomers of fluvastatin in hepatic impairment patients were comparable to those observed in healthy subjects.

Geriatric:

Plasma levels of fluvastatin are not significantly different in patients age > 65 years compared to patients age 21 to 49 years.

Gender:

In a study evaluating the effect of age and gender on fluvastatin pharmacokinetics, there were no significant differences in fluvastatin exposures between males and females, except between younger females and younger males (both ages 21 to 49 years), where there was an approximate 30% increase in AUC in females. Adjusting for body weight decreases the magnitude of the differences seen. For fluvastatin sodium extended-release tablets, the AUC increases 67% and 77% for women compared to men under fasted and high-fat meal fed conditions, respectively.

Pediatric:

Pharmacokinetic data in the pediatric population are not available.

Drug-Drug Interactions:

Data from drug-drug interactions studies involving coadministration of gemfibrozil, niacin, itraconazole, erythromycin, tolbutamide or clopidogrel indicate that the PK disposition of fluvastatin is not significantly altered when fluvastatin is coadministered with any of these drugs.

The below listed drug interaction information is derived from studies using fluvastatin capsules. Similar studies have not been conducted using the fluvastatin sodium extended-release tablet.

Data from drug-drug interaction studies involving fluvastatin and coadministration of either gemfibrozil, tolbutamide or losartan indicate that the PK disposition of either gemfibrozil, tolbutamide or losartan is not significantly altered when coadministered with fluvastatin.

1. National Cholesterol Education Program (NCEP): Highlights of the Report of the Expert Panel on Blood Cholesterol Levels in Children and Adolescents. Pediatrics. 89(3):495-501.1992.

2. Manson, J.M., Freyssinges, C., Ducrocq, M.B., Stephenson, W.P., Postmarketing Surveillance of Lovastatin and Simvastatin Exposure During Pregnancy, Reproductive Toxicology, 10(6): 439-446, 1996.

Fluvastatin sodium extended-release tablets are available as:

80 mg - white to off-white, film-coated, round tablets, debossed with “TV” on one side of the tablet and “7446” on the other side of the tablet, in bottles of 30 and 100. (NDC 0093-7446-56, NDC 0093-7446-01)

Store and Dispense

Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].

Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required). Protect from light.