GPT and Hypokalemia: Enhertu is administered intravenously and may lead to adverse effects including nausea, a decreased white blood cell count, decreased hemoglobin, a decreased neutrophil count, a decreased lymphocyte count, fatigue, a decreased platelet count, increased aspartate aminotransferase, vomiting, increased alanine aminotransferase, alopecia, increased blood alkaline phosphatase, constipation, musculoskeletal pain, a decreased appetite, hypokalemia, diarrhea, and respiratory infection.