Levocarnitine in Treating Patients With Vismodegib-Associated Muscle Spasms

Inclusion Criteria: * Taking vismodegib daily * Subject answers item #1 of muscle spasms questionnaire as moderate or severe intensity at time of screening * At least one muscle spasm per day at time of screening * Muscle spasms onset after starting vismodegib * Willing and able to understand and sign consent form Exclusion Criteria: * Presence of muscle spasms or active neurologic disease prior to start of vismodegib * Use of thyroid medication at the time of screening * Use of Coumadin or acenocoumarol at time of screening * Change in regimen of muscle relaxant medications within four weeks of enrollment * If on stable muscle relaxant medication regimen for 4 weeks prior to enrolling, not willing to maintain muscle relaxant regimen without change during course of the study * Presence of significant renal disease or hemodialysis which would result in dramatic reductions of systemic levocarnitine levels * History of seizures * Known deficiency in carnitine (genetic, etc.) * Any uncontrolled medical condition which may place the patient at increased risk during study participation (at the discretion of the clinical investigator) * Unable or unwilling to comply with study procedures * Pregnant or lactating * All female patients of childbearing potential including those who are within 1 year of last menstrual period will be required to take a pregnancy test during screening, enrollment and at week 0, 4, 8 and 12 * If female of reproductive age, or male partner of female of reproductive age, unwilling to use two medically reliable forms of birth control while on vismodegib * Unwilling to refrain from donation of bodily fluid (blood, platelets, etc.) within 7 months of last vismodegib dose