Interaction
Thursday, January 10th, 2008Xanax Interaction with other medicinal products and other forms of interaction
Pharmacodynamic interactions
Psychotropic Pharmaceuticals
Caution should be exercised if other psychotropic medicinal products are concomitantly used
Increased depression of the activity of the central nervous system can occur when using the
tablets concurrently with psychotropic pharmaceuticals, such as antipsychotics (neuroleptics),
hypnotics, sedatives, antidepressants, narcotic analgesics, anti-epileptic medicinal products,
aneasthetics and sedating antihistamines. However, when taking the tablets in combination
with narcotic analgesics, potentiation of euphoria can occur which may lead to an increased
psychic dependence.
Alcohol
Concomitant intake with alcohol is not recommended. Combination with alcohol potentates
the sedative effect of Xanax.
Clozapine
With clozapine there is an increased risk of respiratory and/or cardiac arrest.
Pharmacokinetic interactions
Since Xanax is metabolised by certain liver enzymes (especially CYP3A4), its effect is
enhanced by pharmaceuticals that inhibit these enzymes. Xanax should therefore be used
with caution in patients taking these medicines and a reduction of dosage may be necessary
when such pharmaceuticals are concomitantly used.
CYP3A4 inhibitors
Itraconazole, a potent CYP3A4-inhibitor, increases AUC and prolongs the elimination half-
life for Xanax. In a study where healthy volunteers were given itraconazole 200 mg/day
and 0.8 mg Xanax, the AUC was increased two-three fold, and the elimination half-life
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was prolonged to about 40 hours. Alterations have also been seen on psychomotor function
affected by Xanax. Itraconazole may enhance the CNS-depressant effects of Xanax
and withdrawal of itraconazole may attenuate the therapeutic efficacy of Xanax.
Concomitant use with potent CYP3A4 inhibitors such as itraconazole, ketoconazole,
voriconazole and HIV protease inhibitors is not recommended. However, if concomitant use
of Xanax and a potent CYP3A4 inhibitor is considered necessary, the Xanax dose
should be reduced to one half or one third.
Nefazodone inhibits CYP3A4 mediated oxidation of Xanax, which results in a doubling
of the plasma concentration of Xanax and risk of intensified CNS effects.
In combination, it is therefore recommended to reduce the Xanax dosage to one half of
the dose.
Fluvoxamine treatment extends the half-life for Xanax from 20 hours to 34 hours and
doubles the Xanax concentration in plasma.
When used in combination, half of the dosage of Xanax is recommended.
Fluoxetine has a moderate inhibitory effect on Xanax-metabolism resulting in increased
plasma concentrations. During concomitant use, the psychomotor effects of Xanax are
therefore intensified. Adjustment of the dose may be required.
Erythromycin inhibits the metabolism of Xanax. The Xanax concentration in plasma
increases by about 50%. The combination may require adjustment of the dose.
Other CYP3A4 inhibitors that are expected to increase the plasma concentration of
Xanax are claritromycin, telitromycin, diltiazem and fluconazole. A dose reduction may
be needed.
Cimetidine reduces the clearance of Xanax which may possibly intensify the effect. The
clinical significance of the interaction has not yet been determined.
CYP3A4 inducers
Patients on concomitant treatment of Xanax and theophylline get a significantly lower
Xanax concentration in plasma than patients only treated with Xanax, possibly
caused by induced metabolism. The clinical significance of this interaction has not yet been
determined.
Carbamazepine seems to induce the Xanax-metabolism resulting in a reduced effect. The
clinical significance of this interaction has not yet been determined.
The effect of Xanax on the pharmacokinetics of other medicinal products
Increase of digoxin plasma levels has been reported with concomitant use of 1 mg Xanax
daily, particularly in the elderly. Therefore patients receiving Xanax and digoxin
concurrently should be closely monitored for signs and symptoms of digoxin toxicity.
One should be prepared for an increase of the muscle relaxing effect (risk of falls) when
Xanax is used during therapy with a muscle relaxant, especially during the beginning of
treatment.
Anxiety Disorders; Overview
An anxiety disorder is an excessive or inappropriate response to stress that leaves you with feelings of apprehension, uncertainty and fear. It can paralyze you into inaction or withdrawal. An anxiety disorder isn’t just a case of “nerves.” According to the Anxiety Disorders Association of America (ADAA), an estimated 40 million Americans, or 18 percent of the population, experience this illness. It is the most common psychiatric condition in the U.S. and costs an estimated $42 billion per year.
Anxiety is expressed physically through a series of responses such as:
a rise in blood pressure
a fast heart rate
rapid breathing
an increase in muscle tensiona decrease in intestinal blood flow, sometimes resulting in nausea or diarrhea
Without treatment, an anxiety disorder can significantly disrupt your life because symptoms usually become progressively worse. Tormented by panic attacks, irrational thoughts and fears, compulsive behaviors or rituals, flashbacks, nightmares or countless frightening physical symptoms, people with anxiety disorders rely heavily on emergency departments and other medical services to address their symptoms.
Their work, family and social lives are disrupted, and some even become housebound. Many individuals who suffer from this disorder have other mental disorders such as depression or substance abuse.
Fortunately, treatment for anxiety disorders is, in general, very effective. Early diagnosis may aid early recovery, prevent the disorder from becoming worse and possibly prevent the disorder from developing into depression. Yet, because of a widespread lack of understanding and the stigma associated with anxiety disorders, only about one third of those who experience them are diagnosed and receive treatment.In recent years, a number of different anxiety disorders have been categorized:
Generalized anxiety disorder (GAD), which affects about 6.8 million Americans (3.1 percent), and it affects twice as many women as men. GAD is characterized by at least six months of a more-or-less constant state of tension or worry not related to any event. If you suffer from GAD, you may always expect a catastrophe to happen. Though you may know your feelings are unrealistic, you cannot control them. The worries that accompany GAD are non-specific and are not as obsessive as the thoughts and worries experienced with obsessive-compulsive disorder. However, more than half the people who suffer from GAD also have another anxiety disorder or depression.
Panic attacks. While GAD is long-lasting and low-grade, panic attacks develop abruptly and generally reach a peak within 10 minutes. They develop without warning and are not necessarily related to any specific event. The word anxiety is derived from the Latin angere, which means to choke or strangle, and many women who suffer from panic attacks report the physical sensation of their throat tightening, cutting off their breath. This physical sensation can lead to additional anxious feelings.
Panic disorder, defined as repeated panic attacks or worry about such attacks, affects about six million Americans (2.7 percent). It typically strikes in young adulthood–before age 24 in roughly half of cases. Women are twice as likely as men to develop panic disorder. People with panic disorder may also suffer from depression; in addition, 30 percent of those with panic disorder abuse alcohol and 17 percent abuse drugs such as cocaine and marijuana. About one-third of people with panic disorder develop agoraphobia, an illness in which they become afraid of being in any place or situation where escape might be difficult or help unavailable if they have a panic attack. So they often won’t leave their home.
Phobias are irrational, involuntary and include overwhelming fears that lead a person to avoid common objects, events or situations, or become excessively anxious as they approach them. While they vary in severity, in some cases the anxiety associated with the feared object or situation can be incapacitating. Most people who suffer from phobias are aware of the irrationality of their fear, and many avoid certain objects or situations or endure intense anxiety. Specific phobias are among the most common medical disorders.
There are three types of phobias: specific, social and agoraphobia.
Specific phobias include fear of animals, heights (acrophobia), air travel (pterygophobia), water, confined spaces (claustrophobia), bridges or other things.
Social phobias, also known as Social Anxiety Disorder (SAD), is caused by a fear of being embarrassed in a social situation, or publicly scrutinized and humiliated. Social phobia is often accompanied by depression and may lead to alcohol or other drug abuse. About 6.8 percent of Americans or 15 million people, have social phobia. Social phobia is equally common among women and men. The disorder typically begins in childhood or early adolescence and rarely develops after age 25.
Agoraphobia is caused by a fear of having a panic attack in public. This fear is so great that it may lead a person to avoid public spaces. About one-third of people with panic disorder develop agoraphobia, which has been somewhat misleadingly described as fear of open spaces–the term having been derived from the Greek word agora, meaning marketplace.