Flurazepam (marketed as Dalmane) is a benzodiazepine derivative which is used as a hypnotic. It also has the highest half-life of any of the benzodiazepines (40-250 hours) and has been known to stay in the bloodstream for up to four days. It is made for relatively short-term use in patients with insomnia. The most common adverse effects are dizziness, drowsiness, lightheadedness and ataxia.