L-Carnitine Reduces Muscle Cramps in Patients taking Vismodegib

Vismodegib is an oral, small-molecule hedgehog pathway inhibitor (HHI) approved for the treatment of locally advanced and metastatic basal cell carcinoma. While an effective treatment option for these conditions, HHI therapy is associated with muscle cramps in a significant number of patients. This adverse effect negatively impacts patient quality of life and patient adherence to the prescribed treatment regimen. Levocarnitine (L-carnitine) is a trimethylated amino acid known to play a critical role in lipid metabolism. It has antioxidant properties, and several studies have illustrated its effectiveness in lessening the severity of muscle cramps in various disease processes. We present three patients who developed muscle cramping associated with vismodegib treatment for basal cell carcinoma. Each was started on L-carnitine therapy, and all three reported a significant decrease in the severity of their muscle cramps to the point that they were able to continue HHI therapy without taking a drug holiday. These cases illustrate a promising treatment option for the most common side effect associated with HHI treatment.