this is a very popular question that we get at the pharmacy. grapefruit juice is one of the ones that we have very good data on as far as what medications it can affect. i would advise to be careful with orange juice because some varieties are enriched with calcium which could possibly bind to a medication and not make it work as well. orange juice can also interact with some medications to treat other conditions like allergies. my rule of thumb is to take medications with a full glass of water -- it really is the best beverage to use to avoid any possible interactions.
is there a problem with orange juice or just grapefruit juice and blood pressure or cholesterol medication?