Fenofibrate

Introduction Overview

Generic Name

fenofibrate

Brand Name

Antara, Fenoglide, Lipofen, TriCor, Triglide, Lofibra, Lipidil Micro, Dom-Fenofibrate, Lipidil Supra, Lipidil EZ

Dosage Form

oral tablets and capsules

Drug Class

Fibric acid derivatives

Pharmacokinetics

Absorption: Fenofibrate demonstrates efficient oral absorption, although absorption rates vary depending on the formulation. Certain branded preparations are recommended to be taken with food to increase bioavailability, as food enhances its absorption. After oral administration, the drug undergoes rapid hydrolysis to fenofibric acid, the active metabolite responsible for lipid-lowering effects. Peak plasma concentrations of fenofibric acid are typically reached within 4 to 6 hours post-dose. Variability in absorption is noted among different fenofibrate products, with newer formulations designed to optimize systemic availability, reduce dosing frequency, and improve gastrointestinal tolerability.

Distribution: Fenofibric acid exhibits extensive plasma protein binding, primarily to albumin, with over 99% bound at therapeutic levels. The volume of distribution is moderate, indicating limited tissue penetration but sufficient presence at target sites such as the liver where lipid metabolism is modulated. Fenofibrate does not significantly accumulate in red blood cells and exhibits no preferential tissue binding beyond plasma proteins. The high protein binding necessitates caution when co-administered with other highly protein-bound drugs due to potential displacement interactions.

Metabolism: Fenofibrate is a prodrug rapidly converted by esterases to fenofibric acid, its active moiety. Fenofibric acid undergoes further metabolism mainly through conjugation with glucuronic acid, forming fenofibric acid glucuronide, which is pharmacologically inactive. Cytochrome P450 enzymes are minimally involved in the metabolism of fenofibrate, reducing the risk of interactions mediated by these enzymes. This metabolic pathway contributes to the drug’s relatively predictable pharmacokinetics. Hepatic metabolism is the primary route, and impairment in liver function may alter drug metabolism and clearance, warranting dosage adjustments.

Elimination: The elimination of fenofibric acid and its conjugates occurs predominantly via renal excretion. Approximately 60 to 70% of the administered fenofibrate dose is recovered in urine, mainly as fenofibric acid glucuronide, and a smaller portion in feces. The elimination half-life ranges from approximately 20 to 30 hours, supporting once-daily dosing regimens. Renal impairment significantly affects fenofibrate clearance, increasing systemic exposure and risk of toxicity. Therefore, careful assessment of renal function and appropriate dose adjustments are critical in patients with renal insufficiency to avoid adverse effects such as myopathy or rhabdomyolysis.

Dosage Forms

Available Dosage Forms:
- Oral tablets and capsules with varied dosages depending on brand and formulation, including: 40 mg, 43 mg, 48 mg, 50 mg, 54 mg, 120 mg, 130 mg, 145 mg, 150 mg, 160 mg, and 200 mg strengths.
- Different brand formulations may recommend administration with or without food to optimize absorption.

Dosages for Adults and Adolescents:
- For hyperlipoproteinemia Type IIa (elevated LDL): TriCor 145 mg once daily; Lofibra and similar brands 160-200 mg once daily with food; Antara 130 mg once daily; Triglide 160 mg once daily; Lipofen 150 mg once daily with food; Fenoglide 120 mg once daily with food.
- For hyperlipoproteinemia Type IIb (elevated LDL and VLDL): doses align with Type IIa regimens.
- For hyperlipoproteinemia Type IV (elevated VLDL): TriCor 48-145 mg once daily; Lofibra and others 54-200 mg once daily with food; Antara 43-130 mg once daily; Triglide 50-160 mg once daily; Lipofen 50-150 mg once daily with food; Fenoglide 40-120 mg once daily with food.
- For hyperlipoproteinemia Type V (elevated chylomicrons plus VLDL): dosing similar to Type IV.

Specific Patient Populations:
- Geriatric patients often start at lower dosages due to renal function considerations, e.g., TriCor 48 mg once daily with careful monitoring and dose adjustments up to 145 mg/day as tolerated.
- Renal impairment necessitates dose reduction and cautious titration.
- Not approved for use in patients under 18 years old.
- Pregnant and breastfeeding women should avoid use; fenofibrate passes into breast milk and potential fetal effects are unknown.
- Dose individualization is important based on lipid profile response and tolerability, with repeat lipid testing every 4 to 8 weeks recommended to guide therapy adjustments.

Mechanism Of Action

Fenofibrate acts primarily as a peroxisome proliferator-activated receptor alpha (PPARα) agonist, which is a nuclear receptor regulating lipid metabolism genes. Upon activation, PPARα forms heterodimers with retinoid X receptors (RXRs) and binds to peroxisome proliferator response elements (PPREs) on DNA, leading to increased transcription of genes involved in fatty acid oxidation, lipoprotein lipase synthesis, and apolipoprotein production.

This receptor activation enhances the catabolism of triglyceride-rich lipoproteins by upregulating the synthesis of lipoprotein lipase, which hydrolyzes triglycerides in very-low-density lipoproteins (VLDL) and chylomicrons, thus reducing plasma triglyceride levels. Fenofibrate also decreases the production of apolipoprotein C-III, an inhibitor of lipoprotein lipase, further facilitating triglyceride breakdown.

Additionally, fenofibrate increases the synthesis of apolipoproteins A-I and A-II, the main protein components of high-density lipoprotein (HDL), contributing to a modest increase in HDL cholesterol levels. The drug also promotes the conversion of small dense LDL particles into larger, less atherogenic LDL particles, improving the lipid profile's overall atherogenicity.

Clinical studies have shown fenofibrate effectively lowers triglycerides and improves lipid profiles; however, large trials have yielded mixed results regarding cardiovascular event reduction, especially when added to statin therapy. The biochemical modulation of lipid metabolism by fenofibrate is also linked to anti-inflammatory and antioxidant effects, which may contribute to vascular protective benefits observed in some subpopulations.

Pharmacological Actions

Potent PPARα agonist enhancing lipid metabolism
Lowers serum triglycerides by increasing lipoprotein lipase activity
Reduces VLDL cholesterol and apolipoprotein C-III levels
Increases HDL cholesterol through upregulation of apolipoproteins A-I and A-II
Modifies LDL particle size to less atherogenic forms
Exerts anti-inflammatory effects on vascular endothelium
Improves overall lipid profile contributing to cardiovascular risk modification
Moderate inhibition of hepatic triglyceride synthesis
Reduces plasma fibrinogen and blood viscosity
Exhibits antioxidant properties protecting lipids from oxidative stress
Enhances fatty acid β-oxidation in liver and muscle tissues
Potential renoprotective effects in patients with diabetic nephropathy
May modulate glucose metabolism and insulin sensitivity

Therapeutic Or Clinical Uses

Treatment of hyperlipoproteinemia Type IIa (elevated LDL cholesterol)
Management of hyperlipoproteinemia Type IIb (elevated LDL and VLDL)
Treatment of hyperlipoproteinemia Type IV (elevated VLDL triglycerides)
Management of hyperlipoproteinemia Type V (elevated chylomicrons and VLDL)
Adjunct therapy to dietary modifications for lowering elevated triglycerides
Used to increase HDL cholesterol in dyslipidemic patients
May be prescribed for mixed dyslipidemia with predominant hypertriglyceridemia
Sometimes considered in patients intolerant to statins
Off-label investigation in diabetic nephropathy for renal protection
Part of lipid lowering strategy in metabolic syndrome
To reduce risk factors associated with pancreatitis in severe hypertriglyceridemia
Complementary treatment in familial hyperlipidemias
May improve lipid abnormalities in patients with type 2 diabetes mellitus
Adjunct in cardiovascular risk reduction where statins alone are insufficient

Side Or Adverse Effects

Gastrointestinal disturbances including nausea, abdominal pain, and dyspepsia
Headache and dizziness
Elevations in liver enzymes such as AST and ALT
Muscle pain, myopathy, and rare cases of rhabdomyolysis leading to acute kidney injury
Allergic reactions including rash, urticaria, and severe skin reactions
Jaundice and signs of hepatotoxicity
Respiratory symptoms such as cough or wheezing
Increased serum creatinine levels indicating renal effects
Pancreatitis reported rarely
Gallstone formation or exacerbation of gallbladder disease
Hypersensitivity reactions including angioedema and anaphylaxis
Fatigue or weakness
Elevated homocysteine levels
Possible thrombocytopenia or hematologic abnormalities
Rare cases of photosensitivity reactions

Precautions

Assess liver function before and during therapy; avoid in active liver disease
Evaluate renal function and adjust dose in renal impairment
Avoid use in patients with gallbladder disease due to risk of cholelithiasis
Monitor for signs of muscle toxicity, especially in elderly or patients with predisposing factors
Use cautiously in diabetic patients and monitor glycemic control
Avoid concomitant use with immunosuppressive drugs unless under close supervision
Discontinue immediately if unexplained muscle pain or weakness occurs
Use with caution in hypothyroid patients and ensure thyroid function is controlled
Not recommended during pregnancy and breastfeeding
Avoid alcohol consumption due to risk of hepatotoxicity and increased triglycerides
Inform patients about the importance of adherence to diet and exercise regimens
Regularly monitor lipid levels to guide therapy adjustments
Be vigilant for allergic and hypersensitivity reactions
Caution when used with other lipid-lowering agents to reduce risk of adverse effects
Ensure patient is not taking interacting cholestyramine or bile acid sequestrants near fenofibrate dose

Warnings

Fenofibrate should not be used in severe renal impairment or dialysis patients
Contraindicated in active liver disease or unexplained persistent liver enzyme elevation
Risk of myopathy and rhabdomyolysis which can lead to acute renal failure
Not to be administered during breastfeeding and pregnancy due to potential risks
May cause gallbladder disease exacerbation including formation of gallstones
Serious hypersensitivity reactions including Stevens-Johnson syndrome have been reported
Use with caution with statins or other lipid-lowering drugs due to increased muscle risk
Monitor kidney function periodically during treatment
Immediate medical consultation required if symptoms of muscle damage or jaundice occur
Avoid use if allergic to fenofibrate or fibric acid derivatives
Increased risk of adverse muscular events in elderly and diabetic patients
Discontinue drug prior to major surgery due to potential for increased bleeding risk
Avoid concomitant use with bile acid sequestrants within 1 hour before or 4-6 hours after fenofibrate
Caution in patients with pre-existing hypothyroidism
Use cautiously in patients with history of pancreatitis

Contraindication

Severe kidney disease including patients on dialysis
Active liver disease or unexplained persistent elevations of liver enzymes
Gallbladder disease such as cholelithiasis or biliary obstruction
Known hypersensitivity or allergy to fenofibrate or other fibric acid derivatives
Breastfeeding mothers
Women who are pregnant or may become pregnant
Patients with severe hepatic impairment or cholestasis
History of statin-induced myopathy or rhabdomyolysis without medical supervision
Concurrent use with certain bile acid sequestrants without appropriate timing
Patients with pre-existing muscle disorders that could predispose to myopathy
Use in pediatric patients under 18 years old
Co-administration with certain immunosuppressive agents without monitoring
Known severe hypersensitivity reactions to fibrates
Co-existing conditions that may increase risk of muscle toxicity without increased monitoring
Patients with uncontrolled hypothyroidism

Drug Interactions

Cholestyramine, colesevelam, and colestipol decrease fenofibrate absorption; separate dosing by 1 hour before or 4-6 hours after
May potentiate the effects of oral anticoagulants like warfarin increasing bleeding risk; requires close INR monitoring
Concomitant use with statins increases risk of myopathy and rhabdomyolysis
Colchicine use with fenofibrate may increase risk of muscle toxicity
Immunosuppressant drugs (e.g., cyclosporine) may increase fenofibrate serum concentrations and toxicity
Drugs inhibiting CYP450 enzymes have minimal interaction but caution advised
Fenofibrate may increase the effect of sulfonylureas, necessitating blood glucose monitoring
Use with parenteral cephalosporins may increase risk of renal toxicity
Interactions with alcohol may increase hepatotoxicity and triglyceride levels
Fenofibrate may displace other highly protein-bound drugs, altering their plasma concentrations
Potential interaction with antihypertensive agents requiring blood pressure monitoring
Concomitant use with thyroid hormones needs monitoring for altered thyroid function
Fenofibrate may reduce the efficacy of oral contraceptives slightly, clinical significance uncertain
Concurrent use with ciclosporin leads to increased risk of renal toxicity
Use with repaglinide or other hypoglycemic agents requires glycemic control monitoring

Preparations Of The Drug

Fenofibrate is available in multiple branded oral tablet and capsule formulations including TriCor, Lofibra, Antara, Triglide, Lipofen, Fenoglide, and others.
Available strengths include 40 mg, 43 mg, 48 mg, 50 mg, 54 mg, 120 mg, 130 mg, 145 mg, 150 mg, 160 mg, and 200 mg.
Various formulations may differ in bioavailability and absorption characteristics; some require administration with food to optimize efficacy.
Extended-release and micronized preparations are available to improve tolerability and convenience.
Packaging varies from blister packs to bottles depending on manufacturer and dosage strength.
Some preparations are designed for once daily dosing, enhancing patient compliance.
Fenofibrate must be stored at room temperature away from moisture, heat, and light to preserve stability.
Not formulated for intravenous or other parenteral routes; solely oral administration is approved.
Generic versions are widely available and may vary in formulation and excipients.
Patient instruction leaflets accompany packaging detailing dosing, precautions, and potential side effects.
Various preparation forms differ in appearance, including tablets and capsules with imprints specific to the brand.
Combination products with other lipid-lowering agents are generally not available; fenofibrate is administered alone.
Preparation selection may depend on patient-specific factors such as food requirement and renal function.
Prescription is required due to the need for monitoring and potential adverse effects.
Brands maintain rigorous quality control to ensure consistent potency and safety profile.