Midazolam, or brand-name Versed, and generic triazolam, or Halcion, are ultra short-acting benzodiazepines, or tranquilizers, while alprazolam, known as Xanax, and lorazepam, or Ativan, are classified as short-acting drugs, reports WebMD. Chlordiazepoxide, or brand-name Librium, and diazepam, known as Valium, have the longest lasting effects. Of the approximately 2,000 different benzodiazepines in production, as of 2015, the Food and Drug Administration has approved only about 15 for use in the United States.
Clonazepam, sold as Klonopin, is a benzodiazepine that treats anxiety, panic and seizures disorders, according to Drugs.com. Elderly individuals are more prone to accidental falls when using Klonopin, and the sedative effects last longer in this age group. Brand drug Doral, from the quazepam group of benzodiazepines, treats insomnia. This fast-acting drug can cause severe allergic reactions, and some individuals perform activities, such as talking on the phone or driving, with no recollection of the event.
Benzodiazepines are central nervous system depressants, and while each class effects brain chemistry differently, they all increase the neurotransmitter gamma-aminobutyric acid, or GABA, explains the National Institute on Drug Abuse. Individuals with insomnia or anxiety disorders feel calm and drowsy after taking these drugs due to the inhibition of brain activity. Although generally well tolerated if taken in regular doses, when combined with alcohol, benzodiazepines are dangerous, cautions WebMD. High doses can cause acute toxicity with symptoms that include drowsiness, slurred speech, breathing difficulty and coma.