While they all accomplish the same goal, different drugs within the class of benzodiazepine can differ by how short-acting they are and how long they last. This variation makes certain drugs ideal for certain conditions—for example, Xanax, Ativan, and Klonopin are commonly used for anxiety disorders because of their quicker onsets, while Librium and Valium can be helpful for things like alcohol withdrawal and seizure disorders because of their long-lasting effect.