From the FDA Drug Label
ASK A DOCTOR BEFORE USE IF YOU HAVE liver or kidney disease. Your doctor should determine if you need a different dose. The FDA drug label does not answer the question.
From the Research
Claritin (loratadine) generally does not significantly affect liver enzymes in most people when taken at recommended doses. Loratadine is metabolized in the liver by the cytochrome P450 system, primarily by CYP3A4 and CYP2D6 enzymes, but it rarely causes liver enzyme elevations or liver injury 1. For healthy individuals, the standard dose is 10 mg once daily, and no routine liver function monitoring is required while taking this medication. However, if you have pre-existing liver disease, your doctor may recommend a lower dose of 10 mg every other day, as clearance of the medication may be reduced in patients with liver impairment. Side effects are uncommon but may include headache, drowsiness, or dry mouth. Unlike some older antihistamines, Claritin is considered liver-friendly and is often preferred for long-term allergy management in patients with liver concerns. If you develop symptoms like yellowing of the skin or eyes, dark urine, or right upper abdominal pain while taking Claritin, contact your healthcare provider immediately as these could indicate liver problems. It's essential to note that while Claritin is considered safe for most people, individual responses can vary, and monitoring by a healthcare provider is crucial, especially for those with pre-existing liver conditions 2. In the context of liver enzyme effects, the most recent and highest quality study available does not directly address Claritin's impact but emphasizes the importance of monitoring and individualized care in patients with liver disease 3. Given the available evidence, Claritin can be considered a safe option for managing allergies in patients with liver concerns, under the guidance of a healthcare provider.