Which liver function tests (LFTs) should I obtain before starting rosuvastatin (rosuvastatin)?

Liver Function Tests Required Before Starting Rosuvastatin

Baseline measurement of hepatic transaminase levels (ALT) should be performed before initiation of rosuvastatin therapy. 1

Recommended Pre-Treatment Laboratory Tests

Rosuvastatin, like other statins, requires specific laboratory monitoring before initiation to ensure patient safety and minimize adverse effects. The following tests should be obtained:

• Alanine aminotransferase (ALT) - Primary test required before starting rosuvastatin 1, 2
• Aspartate aminotransferase (AST) - Often included with ALT as part of standard liver function panel 2
• Total bilirubin - To establish baseline liver function 2
• Albumin - To assess synthetic liver function 2

Rationale for Pre-Treatment Testing

The American College of Cardiology/American Heart Association guidelines specifically recommend baseline measurement of hepatic transaminase levels before initiating statin therapy 1. This recommendation is based on:

1. The need to establish baseline values for comparison during treatment
2. The potential for statins to cause elevations in liver enzymes (occurs in approximately 1.1% of patients taking rosuvastatin versus 0.5% of patients on placebo) 3
3. The importance of identifying pre-existing liver disease that might increase risk of hepatotoxicity

Follow-Up Testing Recommendations

After initiating rosuvastatin:

• Check liver enzymes at 12 weeks after treatment initiation 2
• Subsequent monitoring should be performed if clinically indicated 2
• Routine monitoring of liver enzymes is not recommended in all patients but is warranted for those with baseline abnormalities 2

Important Considerations

• Contraindications: Rosuvastatin is contraindicated in patients with acute liver failure or decompensated cirrhosis 3
• Dose adjustments: Consider lower starting doses in patients with mild to moderate hepatic impairment
• Warning signs: Monitor for symptoms of hepatotoxicity (unusual fatigue or weakness, loss of appetite, abdominal pain, dark-colored urine, or yellowing of the skin or sclera) 1, 3

Management of Abnormal Liver Tests During Treatment

If liver enzyme elevations occur during treatment:

• <3× ULN: Continue current therapy with monitoring
• >3× ULN, asymptomatic: Consider dose reduction
• >3× ULN with symptoms: Consider temporary discontinuation 2

Key Points to Remember

• Serious liver injury from statins is extremely rare (approximately 1/1.14 million patient-treatment years) 2
• Patients with non-alcoholic fatty liver disease (NAFLD) are not at higher risk for serious liver injury from statins 2
• Transient and mild elevations in liver enzymes are common with statin therapy and often resolve spontaneously 4
• Rosuvastatin has similar rates of liver enzyme elevations as other statins 4

By following these recommendations, you can safely initiate rosuvastatin therapy while minimizing the risk of hepatic adverse effects.