From the Guidelines
Elevated alkaline phosphatase (ALP) with normal alanine aminotransferase (ALT) in a 73-year-old female taking fenofibrate suggests medication-induced liver injury, and the first step is to discontinue fenofibrate. The patient's presentation is consistent with cholestatic liver injury, which is a known side effect of fenofibrate, particularly in older adults 1. After stopping the medication, liver enzymes should be monitored every 2-4 weeks until normalization, which typically occurs within 4-8 weeks of discontinuation. During this period, the patient should avoid alcohol and other hepatotoxic medications. If ALP remains elevated despite fenofibrate discontinuation, further evaluation is warranted, including gamma-glutamyl transferase (GGT) to confirm the hepatic origin of ALP elevation, and imaging studies such as ultrasound to rule out biliary obstruction or other hepatobiliary pathologies 1. Age-related factors like primary biliary cholangitis or medication interactions should also be considered. Fenofibrate-induced liver injury occurs through disruption of bile salt export mechanisms, leading to cholestasis, which explains the pattern of elevated ALP with normal ALT. If lipid management remains necessary, switching to a different class of lipid-lowering medication, such as a statin or ezetimibe, may be appropriate after liver enzymes normalize, as these alternatives have a more favorable safety profile 1. Key considerations in managing this patient include careful monitoring of liver enzymes, avoidance of hepatotoxic substances, and potential adjustment of lipid-lowering therapy to minimize the risk of further liver injury.
From the Research
Alkaline Phosphatase Elevation in a 73-Year-Old Female
- The patient is taking fenofibrate, which may not be directly related to the elevation of alkaline phosphatase (ALP) levels, as the provided studies do not mention fenofibrate as a cause of elevated ALP 2, 3, 4, 5.
- Elevated ALP levels can be indicative of cholestatic injury, which is defined as a disproportionate elevation of ALP levels compared to aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels 5.
- The causes of cholestatic pattern include biliary pathology, autoimmune conditions, and other conditions with hyperbilirubinemia 4.
- The evaluation of an ALP elevation determined to be of hepatic origin should include testing for primary biliary cholangitis and primary sclerosing cholangitis 5.
Laboratory Tests for Liver Disease
- ALP is one of the most commonly used laboratory tests for liver disease, along with ALT, AST, bilirubin, and gamma-glutamyl transferase (GGT) 3, 4.
- These tests should be interpreted accurately to guide further workup, treatment, and referral, as prompt treatment can improve the natural history of several liver diseases and reduce the risk of progression to liver cirrhosis 4.
Clinical Guideline for Evaluation of Abnormal Liver Chemistries
- The American College of Gastroenterology (ACG) clinical guideline recommends that clinicians assess abnormal liver chemistries, including ALP, ALT, AST, and bilirubin, on a daily basis 5.
- The guideline provides a framework for evaluating hepatocellular injury and cholestatic injury, including testing for viral hepatitis, nonalcoholic fatty liver disease, and other conditions 5.