Benzodiazepines include Valium, Klonopin, Ativan, and Xanax. Some are very fast working (such as Ativan), some are able to act for long periods of time (upwards of 20 hours), and others are only effective for a short term. What they do have in common, however, are side effects.
The most common side effects include:
Sedation (sleepiness)
Unsteadiness
Weakness
Dizziness
Taking these drugs leaves a person at a very high risk of developing an addiction or dependency to the drug, especially if the drug is used over an extended period of time, such as using it daily for over a year. The body can also build up a tolerance to the drug, and a risk for overdose also becomes possible. Doctors are usually most concerned about the risk of addiction to the drug since that can be one of the most dangerous side effects.
I hope this helps.