Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

238 III. SUBSTANCES OF ABUSEers have moved in opposite directions to maximize two different therapeuticeffects. Xanax XR has a slower onset and longer duration of action to smooththe brain level of alprazolam for 24-hour-a-day effectiveness. Sublingual clonazepamhas been reformulated to overcome the problems some patients haveswallowing pills.Newer Sedative and Hypnotic AgentsIn recent years, a variety of alternatives to the benzodiazepines have becomeavailable to treat both anxiety and insomnia. Buspirone (Buspar) has beenshown to reduce anxiety in generalized anxiety disorders, but it does not suppresspanic attacks, and is not used as a primary treatment of obsessive–compulsive disorder. Buspirone is not abused by alcoholics and drug addicts,and it does not produce withdrawal symptoms on abrupt discontinuation. Likethe antidepressants, buspirone requires several weeks of daily dosing to produceantianxiety effects, which are less dramatic from patients’ point of view thanare the effects produced by the benzodiazepines (Sussman & Stein, 2002).The antidepressants as a class have been shown to possess antipanic andantianxiety effects opening a new range of uses for these medicines in the treatmentof anxiety disorders. The selective serotonin reuptake inhibitors (SSRIs)have emerged as the first-line treatment for many anxiety disorders (Davidson,2003; DuPont, 1997; Jefferson, 1997). Although the earlier antianxiety andanti-insomnia medicines focused exclusively on the benzodiazepine receptors inthe GABA system, the recognition of the importance of serotonin andnorepinephrine neurotransmitters in the management of anxiety and insomnia,and the success of buspirone, have stimulated a search for a new generation ofantianxiety medicines that are not controlled substances (e.g., they are notabused by alcoholics and drug addicts). Recognition of the withdrawal symptomsassociated with abrupt discontinuation of some antidepressants (especiallythose with shorter half-lives and more anticholinergic properties) have shownthat withdrawal is not limited to controlled stubstances (DuPont, 1997).Two nonbenzodiazepine hypnotic agents have been introduced. Zolpidem(Ambien) and Zaleplon (Sonata) are rapid-onset, short duration of action medicinesthat act on the benzodiazepine receptors of the GABA system. Theyhave been shown to reduce insomnia. They have largely replaced the benzodiazepinesas hypnotic medicines, although they lack the anxiolytic, anticonvulsant,and muscle-relaxant properties of the benzodiazepines (Scharf,Mayleben, Kaffeman, Krall, & Ochs, 1991). Zolpidem and zaleplon are reinforcingto alcoholics and drug addicts, underscoring the fact that the abusepotential of both drugs appears to be similar to that of benzodiazepines. Bothmedicines impair memory and performance of complex tasks in ways that aresimilar to the acute effects of benzodiazepines. They do not affect stage 4 sleep,as do the benzodiazepines.