Antianxiety drugs are medicines that calm and relax people with excessive anxiety, nervousness, or tension, or for short term control of social phobia disorder or specific phobia disorder.
Antianxiety agents, or anxiolytics, may be used to treat mild transient bouts of anxiety as well as more pronounced episodes of social phobia and specific phobia. Clinically significant anxiety is marked by several symptoms. The patient experiences marked or persistent fear of one or more social or performance situations in which he or she is exposed to unfamiliar people or possible scrutiny by others, and may react in a humiliating or embarrassing way. The exposure to the feared situation produces an anxiety attack. Fear of these episodes of anxiety leads to avoidance behavior, which impairs normal social functioning, including working or attending classes. The patient is aware that these fears are unjustified.
In psychiatric practice, treatment of anxiety has largely turned from traditional antianxiety agents, anxiolytics, to antidepressant therapies. In current use, the benzodiazepines, the best known class of anxiolytics, have been largely supplanted by serotonin-specific reup-take inhibitors (SSRIs, citalopram, fluoxetine, fluvoxamine and others) which have a milder side effect profile and less risk of dependency. However, traditional anxiolytics remain useful for patients who need a rapid onset of action, or whose frequency of exposure to anxiety provoking stimuli is low enough to eliminate the need for continued treatment. While SSRIs may require three to five weeks to show any effects, and must be taken continuously, benzodiazepines may produce a response within 30 minutes, and may be dosed on an as-needed basis.
The intermediate action benzodiazepines, alprazolam (Xanax), and lorazepam (Ativan) are the appropriate choice for treatment of mild anxiety and social phobia. Diazepam (Valium) is still widely used for anxiety, but its active metabolite, desmethyldiazepam, which has a long half-life, may make this a poorer choice than other drugs in its class. Note that there is considerable variation between individuals in metabolism of benzodiazepines, so patient response may not be predictable. As a class, benzodiazepines are used not only as anxiolytics, but also as sedatives, muscle relaxants, and in treatment of epilepsy and alcoholism. The distinctions between these uses are largely determined by onset and duration of action, and route of administration.
Buspirone (BuSpar), which is not chemically related to other classes of central nervous system drugs, is also a traditional anxiolytic, although it is now considered either a third line or adjunctive agent for use after trials of SSRIs and benzodiazepines. It is appropriate for use in patients who have either failed trials of other treatments, or who should not receive benzodiazepines because of a history of substance abuse problems. Buspirone, in common with antidepressants, requires a two to three week period before there is clinical evidence of improvement, and must be continuously dosed to maintain its effects.
| Antianxiety Drugs | |
| Brand Name (Generic Name) | Possible Common Side Effects Include: |
| Atarax (hydroxyzine hydrochloride) | Drowsiness, dry mouth |
| Ativan (lorazepam) | Dizziness, excessive calm, weakness |
| BuSpar, Buspirone (buspirone hydrochloride) | Dry mouth, dizziness, headache, fatigue, nausea |
| Centrax (pazepam) | Decreased coordination, dizziness, drowsiness, fatigue, weakness |
| Librium, Libritabs (chlordiazepoxide) | Constipation, drowsiness, nausea, swelling |
| Miltown, Equanil (meprobamate) | Diarrhea, bruising, fever, headache, nausea, rash, slurred speech |
| Serax (oxazepam) | Dizziness, fainting, headache, liver problems, decreased coordination, nausea, swelling, vertigo |
| Stelazine (trifluoperazine hydrochloride) | Abnormal glucose in urine, allergic reactions, blurred vision, constipation, eye spasms, fluid retention and swelling |
| Tranxene, Tranxene-SD (clorazepate dipotassium) | Drowsiness |
| Valium (diazepam) | Decreased coordination, drowsiness, light-headedness |
Benzodiazepines are controlled drugs under federal law. Buspirone is not a controlled substance and has no established abuse potential.
Benzodiazepines should be administered 30 to 60 minutes before exposure to the anticipated stress. Dosage should be individualized to minimize sedation. The normal dose of alprazolam is 0.25–0.5 mg. The usual dose of lorazepam is 2–3 mg. Doses may be repeated if necessary.
Buspirone is initially dosed at 5 mg t.i.d. (3 times a day.) Increase the dosage 5 mg/day, at intervals of two to three days, as needed. Do not exceed 60 mg/day. Two to three weeks may be required before a satisfactory response is seen.
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Author Info: Samuel Uretsky PharmD, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Medicine, 2002 |