There are three main classes of medicines used to treat anxiety disorders which include Benzodiazepines, anti depressants and selective serotonin reuptake inhibitors (SSRIs). Benzodiazepines (alprazolam, clonazepam, diazepam, and lorazepam etc) are mostly used because of their short term effectiveness as they may effect within an hour.
They come with their side effects such as drowsiness, upset stomach etc that should be taken care of. Therefore when undergoing the treatment, you and your doctor should cooperate and work as a team. If one medicine does not affect you very well, inform your doctor so that he may choose an alternate for you. Once the medication starts taking effect, you will feel in control and relaxed. Patience and strength during your medication will lead you to your newer self, calm and relaxed.