All passenger items must undergo security screening. It is recommended that medication be clearly labeled to facilitate the screening process.Rules state they must be in original prescription bottles. All prescription medicines are allowed on airplanes, whether in a carry-on or checked bag. Some states specifically forbid carrying prescription drugs in a "generic" or unlabeled container. Texas has no express law on this subject. With your doctor's OK, most pharmacies will readily fill a prescription for 3 months. Can you bring foreign drugs into the U.S.? Or refill a foreign prescription at a U.S. pharmacy? Awareness of drug reactions and the synergistic effects of drugs combined with other medicines and in some instances, food, are imperative.