Anxiety disorders monoamine oxidase inhibitors

Monoamine Oxidase inhibitors (MAOis). Many, though not all, antidepressants are effective treatments for social anxiety disorder. Although they do not provide rapid symptom relief and may even transiently worsen anxiety symptoms during the first 1-2 weeks of treatment, antidepressants have the advantage of treating comorbid depression. 

The growth during the 1990s in the use of antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), for the treatment of anxiety disorders represented a major advance in the pharmacotherapy of anxiety. The efficacy of tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) had been established alongside their antidepressantw actions several decades... 

SRls are currently the most prevalent pharmacological treatment used for panic disorder [see Westenberg and Den Boer, Chapter 24, in this volume], even though tricyclic antidepressants, monoamine oxidase inhibitors [MAOls], and benzodiazepines are also effective. The efficacy of the SRI antidepressants and the observation that initially they may induce deterioration of symptoms [which is usually not the case with treatment of depressed patients with the same medications] raise issues related to the pathobiology of anxiety and its comorbidity with depression. 

It became obvious, however, that psychostimulants were not effective in situations of lowered arousal resulting from mood depression. In the 1950s, antidepressants such as the monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants (TCAs) became recognized as more effective in treating depression. The differentiation between arousal and mood thus became clearer. It is through the action of drugs that sedate and thus reduce anxiety versus those drugs that do not sedate but are anxiolytic that the basic concepts of anxiety have forcibly to be reconsidered. This inevitably led to the need for a reconceptualization of psychotropic modes of action in relation to psychiatric disorders. 

Arguably the first modern class of antidepressants, monoamine oxidase inhibitors (MAOIs) were introduced in the 1950s but are now rarely used in clinical practice because of toxicity and potentially lethal food and drug interactions. Their primary use now is in the treatment of depression unresponsive to other antidepressants. However, MAOIs have also been used historically to treat anxiety states, including social anxiety and panic disorder. In addition, selegiline is used for the treatment of Parkinson s disease (see Chapter 28). 

Panic disorder is one of the most prevalent psychiatric disorders in industrialized countries. It is often associated with agoraphobia and has an estimated prevalence of between 1% and 6%. The use of imipramine in the treatment of anxiety by Klein and Fink, and the discovery by William Sargant that monoamine oxidase inhibitors (MAOIs) were effective in the treatment of "atypical depression" over 30 years ago led to the investigation of the efficacy of such treatments in patients with panic disorder. Since that time, such drugs have been shown to attenuate the symptoms of panic in addition to those of phobic avoidance and anticipatory anxiety. As both the... 

Antidepressant drugs of various classes (tricyclics, monoamine oxidase inhibitors, SSRIs) have broad efficacy in generalized anxiety and in panic disorder, for which they are the treatments of choice (6,7). While not likely to cause benzodiazepine-like dependence or abuse, they do have a significant therapeutic latency, and the older drugs are very toxic in overdose. 

Affective and Mental Disorders. Anxiety and emotional instability can be associated with psychogenic reactions, such as vasovagal syncope, that may appear to be drug related. Medications used to treat these disorders may potentiate the activity of ophthalmic medications. The use of monoamine oxidase inhibitors or tricyclic antidepressants can enhance the systemic effects of topically applied phenylephrine and a2-adrenergic agonists. 

Monoamine oxidase inhibitors are used to treat depression, atypical depression, bulimia, posttrau-matic stress reactions, obsessive-compulsive disorder, panic attacks, narcolepsy, phobias, hypochondria, anxiety, and many other psychiatric disorders as well as night tremors, parkinsonism, postural hypotension, headache, and aphthous stomatitis. 

The mood and anxiety disorders in their various permutations constitute a major source of personal suffering and impaired ability to engage in productive Avork and interpersonal relationships. Between 5 and 9% of women and between 2 and 3% of men meet the diagnostic criteria for major depression at any time 10-25% of all women suffer major depression sometime in their lives, while 5-10% of men will develop major depressive disorder (American Psychiatric Association, 1994). The anxiety disorders obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), panic disorder, and generalized anxiety disorder (GAD) show lifetime prevalence rates of approximately 2.5%, 7%, 2.5%, and 5% respectively. Between 3 and 13% of individuals in community samples are regarded to meet the diagnostic criteria for social phobia. Mood and anxiety disorders are common comorbidities (American Psychiatric Association, 1994) and the most common antidepressant medications including the serotonin reuptake inhibitors, the mixed serotonin-catecholamine reuptake inhibitors, the tricyclic antidepressants, and the monoamine oxidase inhibitors, are all effective treatments for anxiety and panic attacks. 

By the 1970s and early 1980s it was recognized that certain tricyclic antidepressants and monoamine oxidase (MAO) inhibitors were effective in treating panic disorder and one tricyclic antidepressant (clomipramine) was effective in treating obsessive-compulsive disorder. Thus, there began to be recognized that some antidepressants overlapped with anxiolytics for the treatment of anxiety disorder sub-types or for mixtures of anxiety and depression (Fig. 8—8). However, either anxiolytics... 

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