Drug Groups

illicit; approved; investigational

Description

A triazolobenzodiazepine compound with antianxiety and sedative-hypnotic actions, that is efficacious in the treatment of panic disorders, with or without agoraphobia, and in generalized anxiety disorders. (From AMA Drug Evaluations Annual, 1994, p238)

Indication

For the management of anxiety disorder or the short-term relief of symptoms of anxiety and for the treatment of panic disorder, with or without agoraphobia.

Pharmacology

Alprazolam, a benzodiazepine, is used to treat panic disorder and anxiety disorder. Unlike chlordiazepoxide, clorazepate, and prazepam, alprazolam has a shorter half-life and metabolites with minimal activity. Like other triazolo benzodiazepines such as triazolam, alprazolam may have significant drug interactions involving the hepatic cytochrome P-450 3A4 isoenzyme. Clinically, all benzodiazepines cause a dose-related central nervous system depressant activity varying from mild impairment of task performance to hypnosis. Unlike other benzodiazepines, alprazolam may also have some antidepressant activity, although clinical evidence of this is lacking.

Toxicity

Oral, mouse: LD₅₀=1020 mg/kg. Symptoms of overdose include confusion, coma, impaired coordination, sleepiness, and slowed reaction time.

Affected Organisms

Biotransformation

Hepatic. Hydroxylated in the liver to α-hydroxyalprazolam, which is also active. This and other metabolites are later excreted in urine as glucuronides.

Absorption

Readily absorbed from the gastrointestinal tract. Bioavailability is 80-90%.

Half Life

6.3-26.9 hours

Protein Binding

80% (mainly to albumin)

Elimination

Alprazolam and its metabolites are excreted primarily in the urine.

Clearance

* 2.13 +/- 0.54 mL/min/kg [CYP3A inducers]
* 0.90 +/- 0.21 mL/min/kg [without CYP3A inducers]

References

External Links