A: That’s true, unless you’re drinking decaf. It’s best not to combine large amounts of caffeine with any drug that has stimulant effects, such as pseudoephedrine (which is found in some cold and allergy meds), because the caffeine can heighten the drug’s side effects, which may include weakness, nausea, and an irregular heartbeat.
Meanwhile, certain antibiotics, such as ciprofloxacin (Cipro), can interfere with the breakdown of caffeine in your body, extending the amount of time it stays in your system and prolonging its effects, such as insomnia or a bad case of the jitters. The herbal supplement echinacea can also do this.
Photos courtesy of and copyright stock.xchng, http://www.sxc.hu/