Norepinephrine generalized anxiety

Venlafaxine is approved by the U.S. Food and Drug Administration for the treatment of both major depression and generalized anxiety disorder. Preliminary data suggest that it might also have a role in the treatment of chronic pain conditions and perhaps other disorders against which SSRIs are effective. Serotonin reuptake inhibition is prominent at lower doses of venlafaxine at higher doses, inhibition of norepinephrine reuptake becomes more significant. 

Disadvantages of the benzodiazepines include the risk of dependence, depression of central nervous system functions, and amnestic effects. In addition, the benzodiazepines exert additive central nervous system depression when administered with other drugs, including ethanol. The patient should be warned of this possibility to avoid impairment of performance of any task requiring mental alertness and motor coordination. In the treatment of generalized anxiety disorders and certain phobias, newer antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), are now considered by many authorities to be drugs of first choice (see Chapter 30). 

In addition to its efficacy as a first-line antidepressant, mirtazapine may have enhanced efficacy due to its dual mechanism of action (Fig. 7—3), especially in combination with other antidepressants that block serotonin and/or norepinephrine reuptake. This will be discussed below in the section on antidepressant combinations. Mirtazapine may also have utility in panic disorder, generalized anxiety disorder, and other anxiety disorders, but has not been intensively studied for these indications. 

SSRIs show efficacy in social phobia, and combined serotonin and norepinephrine uptake inhibitors are effective in generalized anxiety disorder. 

Noradrenergic model. This model suggests that the autonomic nervous system of anxious patients is hypersensitive and overreacts to various stimuli. The locus ceruleus may have a role in regulating anxiety, as it activates norepinephrine release and stimulates the sympathetic and parasympathetic nervous systems. Chronic noradrenergic overactivity down regulates 02-adrenoreceptors in patients with generalized anxiety disorder (GAD) and posttraumatic stress disorder (PTSD). Patients with social anxiety disorder (SAD) appear to have a hyperresponsive adrenocortical response to psychological stress. 

Venlafaxine is a serotonin and norepinephrine reuptake inhibitor that potentiates norepinephrine, serotonin, and dopamine neurotransmitter activity in the CNS by inhibiting their neuronal reuptake. Effexor, Effexor XR are used in treatment of major depressive disorder. Effexor XR is used in treatment of generalized anxiety disorder and treatment of social anxiety disorder. 

Corynomycollc acid isolated from the cell walls of Cor-ynebacterium sp. or related organisms exhibit immunostimu-lant properties.Duloxetine is a serotonin-norepinephrine reuptake inhibitor used in major depressive disorder, general anxiety disorder, stress urinary incontinence,diabetic peripheral neuropathy, fibromyalgia,and chronic musculoskeletal pain associated with osteoarthritis and chronic lower back pain. Fluoxetine is a serotonin-uptake inhibitor used as an antidepressant and for treatment of anxiety, alcoholism, and bulimia. " ... 

Both norepinephrine and serotonin have been implicated in anxiety disorders and depression. Although scientists generally believe that MAOIs and TCAs are beneficial because they target serotonin systems, there is some evidence that specifically targeting the norepinephrine system can help some patients. Certain TCAs preferentially activate norepinephrine systems. These and other norepinephrine-selective drugs have been shown to help alleviate some cases of depression. 

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