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Monitoring patient compliance
Helping to achieve desired blood levels and avoid toxicity
Alprazolam (Xanax), a drug used to treat panic and anxiety disorders, is a triazolobenzodiazepine with the same ring structures as triazolam. It is considered an intermediate benzodiazepine with a half-life of 6 to 20 hours and a rapid onset of action with peak plasma levels reached within 1 to 2 hours of dosing. Typical daily doses range from 0.75 to 3.0 mg and Xanax tablets are available in 0.25 mg, 0.5 mg, 1 mg, or 2 mg doses.
Hepatic biotransformation of alprazolam produces hydroxylated metabolites, which are excreted in urine as glucuronide metabolites. Alprazolam has 2 major metabolites: alpha-hydroxy-alprazolam and 4-hydroxyalprazolam. A benzophenone derivative is also found in humans. Only the hydroxy-alprazolams are biologically active with approximately one half the activity of the parent drug. Since the metabolites are only present in trace amounts in serum, quantitation of metabolites is not clinically significant.
Alprazolam may have central nervous system (CNS) depressant effects. Patients using alprazolam should avoid other CNS depressant drugs, as well as ingestion of alcohol.
When discontinuing therapy in patients who have used alprazolam for prolonged periods, the dose should be decreased gradually over 4 to 8 weeks to avoid the possibility of withdrawal symptoms, especially in patients with a history of seizures or epilepsy, regardless of their concomitant anticonvulsant drug therapy. Patients on short-acting benzodiazepines may be switched to longer-acting drugs (eg, diazepam), which produce a gradual decrease in drug concentration and decrease the risk of withdrawal symptoms.
Therapeutic range: 5-25 ng/mL
Some patients respond well to levels of 25-55 ng/mL.
The assessment of treatment with alprazolam should be based on clinical response. Effectiveness of treatment can be determined by the reduction of symptoms of anxiety and panic disorders.
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