Do you need to check liver function when prescribing a statin (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor) to a patient?

Liver Function Testing Requirements for Statin Therapy

Baseline liver function tests should be performed before initiating statin therapy, but routine monitoring is not recommended unless symptoms of hepatotoxicity develop. 1, 2

Initial Assessment Before Starting Statins

• Baseline measurement of hepatic transaminase levels (ALT) should be performed before initiation of statin therapy to identify pre-existing liver conditions that might influence statin selection or dosing 2, 1
• Normal liver function tests from up to 2 months ago are sufficient as baseline values 3
• Baseline assessment helps identify patients with modest transaminase elevations (<3 times the upper limit of normal [ULN]) who can still receive statin therapy but may require more careful monitoring 1

Routine Monitoring After Starting Statins

• Routine periodic monitoring of liver enzymes is NOT recommended after starting statin therapy if baseline levels are normal 1, 2
• In patients treated with statins, routine measurements of transaminase levels are not useful and have been given a Class III: No Benefit recommendation (Level of Evidence: C-LD) 2
• The risk of serious liver injury with statin therapy is extremely rare and did not differ from placebo in clinical trials 1, 4

When to Check Liver Function Tests During Statin Therapy

• Liver function tests should be measured ONLY if symptoms suggesting hepatotoxicity arise, including: 2, 1
  • Unusual fatigue or weakness
  • Loss of appetite
  • Abdominal pain
  • Dark-colored urine
  • Yellowing of the skin or sclera (jaundice)
• If symptoms develop, a complete hepatic panel should be obtained including AST, ALT, total bilirubin, and alkaline phosphatase 2

Special Considerations

• For patients with chronic, stable liver disease (including non-alcoholic fatty liver disease), it is reasonable to use statins after obtaining baseline measurements and determining an appropriate monitoring schedule 2, 1
• Moderate-intensity statin therapy should be used in patients with characteristics that may predispose them to statin-associated adverse effects, including impaired hepatic function 2, 1
• Statin therapy need not be avoided in patients with preexisting liver dysfunction such as non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, or compensated chronic liver disease if clinically indicated 4, 5

Management of Abnormal Liver Tests

• If ALT elevations are less than 3 times ULN during therapy, continue statin therapy with follow-up testing 1, 6
• If ALT elevations are greater than 3 times ULN, consult with healthcare provider to evaluate the net benefit of continuing statin therapy versus adjusting or discontinuing medication 1, 4
• Decreasing the statin dose may be considered when two consecutive values of LDL-C are <40 mg/dL 2

Common Pitfalls to Avoid

• Unnecessary repeat testing of liver function tests before starting statin therapy when recent normal values are available 3
• Routine monitoring of liver function tests in asymptomatic patients on statin therapy, which may lead to unnecessary testing and potential discontinuation of beneficial therapy 3, 7
• Avoiding statins in patients with mild to moderate baseline liver enzyme elevations, particularly those with metabolic syndrome or non-alcoholic fatty liver disease, who may actually benefit from statin therapy 5, 4
• Discontinuing statins prematurely due to mild transient elevations in liver enzymes, which rarely progress to serious liver injury 4, 6