| Article ID: | 243513 |
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alprazolam chemical structure
Alprazolam | |
| IUPAC name | |
| CAS number 28981-97-7 | ATC code N05 BA12 |
| Chemical formula | C 17 H 13 ClN 4 |
| Molecular weight | 308.8 |
| Bioavailability | 80-90% |
| Metabolism | Liver |
| Elimination half life | 6-27 hours (11 hour avg.) |
| Excretion | Urine |
| Pregnancy category | D |
| Legal status | USA DEA Schedule IV |
| Route of administration | Oral |
Indicated for:
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Contraindication
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Alprazolam has a calming effect, with the most common side effects being drowsiness, clumsiness, and to a lesser extent, fatigue, and headache. It can also have more adverse effects, such as blurred vision, slurred speech or dysarthria , and changes in personality. It may be habit forming and users often develop a tolerance to its initial effects, although its anxiolytic efficacy remains intact. Physical and/or psychological dependence may develop after several weeks of alprazolam treatment. There is now a general consensus among many psychiatrists that alprazolam (a so-called 'high-potency' benzodiazepine) poses a particularly high risk for abuse and dependence. Withdrawal after long-term use should be done slowly over a period of weeks to avoid serious withdrawal symptoms such as agitation, rebound anxiety, muscle cramps and possible seizure s. Some patients may benefit from a more gradual dosage reduction and/or discontinuation and substitution with diazepam .
The main medical indications are as follows:
1. Treatment of panic disorder (with or without agoraphobia ). Alprazolam is very effective in preventing panic attacks. However, despite its efficacy, many psychiatrists are reluctant to use alprazolam for this condition because of the possibility of dependence and interdose anxiety due to its short-acting nature. An extended-release formulation of alprazolam known as Xanax XR® was introduced in 2001 and is often preferred.
2. As needed (PRN) therapy of panic attacks , 4 to 6 doses per month are the acceptable limit. If dependence seems to develop and/or the limit is exceeded therapy may be reconsidered and/or stopped.
3. Initial therapy together with selective serotonin reuptake inhibitors such as paroxetine , sertraline , or fluoxetine to alleviate initial SSRI-induced anxiety while waiting for the agent to begin working. Clinical experience has shown, however, that SSRIs may actual provoke panic attacks in otherwise healthy individuals and cause sexual dysfunction . In these cases, a tricyclic antidepressant may be used. Buspirone may also be useful in conjunction with alprazolam in cases of generalized anxiety disorder .
4. Long-term treatment of severe generalized anxiety disorders if other therapies either do not work or are contraindicated. Duration of therapy in this case is often four months or longer. The indication must be cautiously made by a specialized psychiatrist taking into account both the individual suffering, quality of life, loss in social performance and the risk of dependence.
5. The drug may be used by specialists to treat severe cases of Borderline Personality Disorder . Some studies have shown positive results.
In the United States , alprazolam is a prescription drug and is assigned to Schedule IV of the Controlled Substances Act by the Drug Enforcement Administration . Internationally, alprazolam is included under the United Nations Convention on Psychotropic Substances .
Alprazolam is a triazolobenzodiazepine , that is, a benzodiazepine with a triazolo-ring attached to its structure. Alprazolam binds to the GABA A subtype of the GABA recpetor , increasing inhibitory effects of GABA within the central nervous system. The binding site for benzodiazepines is distinct from the binding site for GABA on the GABA receptor.
Unlike other benzodiazepines, alprazolam may also have some antidepressant activity, although clinical evidence of this is lacking.
Alprazolam is readily absorbed from the gastrointestinal tract. The peak plasma concentration is achieved in 1-2 hours. Most of the drug is bound to plasma protein, mainly albumin . Alprazolam is hydroxylated in the liver to α-hydroxyalprazolam, which is also active. This and other metabolite s are later excreted in urine as glucuronide s. Some of the alprazolam is also excreted in unchanged form.
Alprazolam, like other benzodiazepines, has the potential for abuse, especially in addiction-prone individuals. It is not manufactured illegally, but is sometimes diverted to the black market. Nasal (by snorting of ground tablets) administration sometimes occurs. The state of relaxation, anxiolysis and disinhibition provided by benzodiazepines is rewarding. It is sometimes used adjunctively with other recreational drugs to relieve the panic or distress of dysphoric reactions to psychedelic s such as LSD and also to promote sleep (hypnosis) in the "come-down" period following use of recreational drugs with stimulant or insomniac properties (such as LSD , cocaine , amphetamine , and MDMA ).