Travacalm Original Tab It is used to treat travel sickness because it contains a combination of dimenhydrinate, hyoscine hydrobromide and caffeine. Hyoscine hydrobromide is an anticholinergic drug. Anticholinergics have a wide variety of actions and are well known for their use in the prevention of travel sickness. Dimenhydrinate is longer acting than hyoscine hydrobromide. Both of these ingredients may cause drowsiness. The addition of caffeine helps to counteract the drowsiness.