Codeine cough syrup & monster energy drink, is it okay to mix the 2?

No contraindication: But am concerned about the reasons for taking both. Energy drinks are essentially caffeine, with some of them containing herbal remedies like ginko and often containing vitamins (which are mostly useless, and are just urinated out if you take excess amounts). People who feel tired should treat the cause of being tired, and not use stimulants (whether caffeine or others) - a vicious cycle develops.