What are the side effects of fenofibrate?

Side Effects of Fenofibrate

Fenofibrate is generally well tolerated, but requires monitoring for several important adverse effects including renal function changes (transient creatinine elevation), hepatic transaminase elevations, pancreatitis, pulmonary embolism, and muscle-related symptoms.

Common and Expected Side Effects

Renal Effects

• Serum creatinine elevations occur commonly and are typically transient and reversible upon discontinuation 1
• Average increase of 0.113-0.136 mg/dL (10-12 mmol/L) 1
• Critical monitoring requirement: Check renal function before initiation, within 3 months, then every 6 months 1
• Important caveat: The creatinine rise does not indicate actual renal damage and should not automatically prompt discontinuation 2
• Contraindicated if eGFR <30 mL/min per 1.73 m²; dose reduction to ≤54 mg/day if eGFR 30-59 1

Hepatic Effects

• Transaminase elevations that are usually transient, minor, and asymptomatic 3
• Risk of ALT elevation >5 times upper limit of normal, particularly when combined with statins 1
• Monitor hepatic transaminases at baseline and as clinically indicated 1

Gastrointestinal Effects

• Gastrointestinal disturbances are common 3, 4
• Pancreatitis has been reported 1, 5
• Cholelithiasis risk: Fenofibrate increases cholesterol excretion into bile, potentially leading to gallstone formation 5, 4

Serious Adverse Effects Requiring Vigilance

Venothromboembolic Events

• Higher rates of pulmonary embolism and deep vein thrombosis compared to placebo 1, 5
• In the FIELD trial: PE occurred in 1% fenofibrate vs 0.7% placebo (p=0.022); DVT in 1% vs 1% (p=0.074) 5

Muscle-Related Toxicity

• Myopathy, myalgia, and muscle fatigue can occur 6, 7
• Rhabdomyolysis risk, especially when combined with statins (particularly gemfibrozil, which should NOT be used with statins) 1
• Fenofibrate with low-to-moderate intensity statins has similar myopathy rates as statin monotherapy 1
• Monitor for muscle pain, tenderness, or weakness 5

Hematologic Changes

• Mild to moderate decreases in hemoglobin, hematocrit, and white blood cells 5
• Thrombocytopenia and agranulocytosis reported rarely 5
• Monitor blood counts during first 12 months 5

Hypersensitivity Reactions

• Acute reactions: Anaphylaxis and angioedema (can be life-threatening) 5
• Delayed reactions: Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS syndrome 5
• Photosensitivity reactions and rash 6

Metabolic and Laboratory Abnormalities

• Paradoxical severe HDL-C decreases (as low as 2 mg/dL) reported in diabetic and non-diabetic patients 5
  • Can occur within 2 weeks to years after initiation
  • Check HDL-C within first few months; withdraw fenofibrate if severely depressed 5
• Gout and hypoglycemia identified as potential adverse effects 6
• Blood creatine phosphokinase increases 6
• Prothrombin time prolongation (particularly important with concurrent anticoagulant use) 5, 6

Drug Interaction Concerns

Anticoagulants

• Potentiates coumarin-type anticoagulants, prolonging PT/INR 5
• Requires frequent PT/INR monitoring and dose adjustment until stabilized 1, 5

Statins

• Gemfibrozil should never be initiated with statins due to rhabdomyolysis risk 1
• Fenofibrate may be considered with low-to-moderate intensity statins only if benefits outweigh risks 1

Colchicine

• Cases of myopathy and rhabdomyolysis reported with concurrent use 5

Timing of Adverse Events

• Most adverse events occur within the first 3 months of therapy 6
• Skin rash, liver/renal dysfunction, and muscle tenderness typically appear early and are reversible 4

Gender Considerations

• Female patients may require closer monitoring for adverse events 6
• In women with well-controlled diabetes, CVD event rates were paradoxically higher with fenofibrate-simvastatin vs simvastatin alone 1

Reassuring Safety Data

• No increased risk for: elevated hepatic transaminases (when used alone), cancer, hemorrhagic stroke, or non-cardiovascular mortality 1
• When combined with statins: similar rates of myopathy, myositis, rhabdomyolysis, and cancer death as statin monotherapy 1
• Extensive European experience (6 million patient-years) indicates severe side effects are unlikely 4