Add these and cough syrups like them to your list on contraindicators. Just after taking my first two tablespoons of Dayquil, I noticed a warning not to use it if you're also taking MAO inhibitors for Parkinson's. Imagine my surprise! I quickly called my neuro and learned there can be problems with elevated blood pressure, but two tablespoons of Dayquil/Nyquil plus 5 mg of selegeline twice a day probably wouldn't hurt me; just don't take any more. He said it could be more serious with some of the more powerful MAO inhibitors. I guess if you need some cough syrup you're out of luck. FYI. Keith Chancey