The FDA has required that the labels of all carbidopa/levodopa-containing products (Crexont, Dhivy, Duopa, Rytary, Sinemet, Sinemet CR, Stalevo, Vyalev) include a warning about the risk of vitamin B6 (pyridoxine) deficiency and vitamin B6 deficiency-related seizures associated with their use. The combination of carbidopa/levodopa is the most effective treatment for the motor symptoms of Parkinson's disease and recent evidence favors its early use.