Differential Diagnosis for Elevated LFT and AST in a Patient on Lexapro and Lamictal

• Single most likely diagnosis:
  • Drug-induced liver injury (DILI): Both Lexapro (escitalopram) and Lamictal (lamotrigine) can cause liver enzyme elevations, although it is more commonly associated with other medications. The combination of these two drugs may increase the risk of liver injury.
• Other Likely diagnoses:
  • Non-alcoholic fatty liver disease (NAFLD): Given the prevalence of NAFLD in the general population and its association with metabolic syndrome, this diagnosis is plausible, especially if the patient has risk factors such as obesity or diabetes.
  • Viral hepatitis: Although less common, viral hepatitis (A, B, C, D, or E) can cause elevated liver enzymes. The patient's vaccination status and risk factors for viral exposure should be considered.
• Do Not Miss diagnoses:
  • Acetaminophen toxicity: Even if not explicitly mentioned, acetaminophen is a common over-the-counter medication that can cause severe liver injury at high doses. It's crucial to inquire about its use.
  • Wilson's disease: A genetic disorder leading to copper accumulation in the liver, which can cause liver enzyme elevations. Although rare, missing this diagnosis could lead to severe liver damage.
• Rare diagnoses:
  • Autoimmune hepatitis: An autoimmune condition where the body's immune system attacks liver cells, leading to inflammation and liver damage. It is less common but should be considered if other causes are ruled out.
  • Budd-Chiari syndrome: A rare condition caused by thrombosis of the hepatic veins, leading to liver enlargement and elevated liver enzymes. It is essential to consider in patients with risk factors for thrombosis.