Klonopin (Clonazepam) and Ativan (Lorazepam) are both benzodiazepines used to treat anxiety and seizures. Klonopin has a longer duration (half-life of 18-50 hours), making it suitable for chronic anxiety and seizure disorders. Ativan, with a shorter duration (half-life of 10-20 hours), is often used for acute anxiety and preoperative sedation. Klonopin is more potent, requiring lower doses, while Ativan has a quicker onset but generally needs higher doses. Both carry risks of dependency and side effects like drowsiness, but Klonopin may have a lower withdrawal risk due to its longer half-life.