Anti depressant Medicines Information

 

Antidepressants Medicines

The development of antidepressant drugs, sometimes referred to as “psychic energizers” represents one of the outstanding successes of modern psychopharmacology. The two major categories of antidepressant drugs are: (i) the tricyclic group of which imipratnine and amitriptyline are the most widely used; and (ii) the monoamine oxidase inhibitors (MAOIs), of which tranylcyprornaine and pheneizine are the best known. The classic indication for antidepressant medication is endogenous depression; however, these drugs are also helpful in the treatment of agitated depressions and phobic anxiety states. The central factor in all types of depression is a loss of ability to experience pleasure, associated with feelings of personal incompetence.

Classification Of Depressions:

Depression is an affective disorder which afflicts many individuals. The psychiatric term “affect” refers to the feelings — pleasant and unpleasant — which one experiences. Such feelings may be mild or strong, but all together they regulate the emotional and mental state at any one time.
Reactive depression is characterized by a well-defined precipitating stress, such as the loss of a loved one, adverse effects of drugs or certain disease state.
Endogenous depression is characterized by a definite onset of depressive symptoms unrelated to any significant external event.
Classification of Antidepressants: The antidepressants may be classified as under:
1. Noradrenaline-Reuptake Inhibitors: (i) Tricyclics (Tertiary Amines): Amitriptyline, Doxepin,lmipramine etc. (ii) Tricyclics (Secondary Amines): Amoxapine, Maprotiline, Nortriptyline etc.
2. Serotonin-Reuptake Inhibitors: Fluoxetine, Paroxetine, Sertraline etc.
3. Atypical Antidepressants: Bupropion, Trazodone etc.
4. Monoamine Oxidase Inhibitors (MAOIs): Pheneizine, Tranylcypromine etc.

Tricyclic Antidepressant: Tricyclic antidepressants are chemically related to the phenothiazine tranquillizers, and like the phenothiazines most of them exert a sedative effect during the first few days of their use. However, after several weeks of treatment, most patients respond quite differently, and sedation is minimal. In general these drugs are most effective for treating moderate to severe depressive illness, associated with psychomotor and physiological changes; such as loss of appetite and sleep disturbances.

Doxepin: This agent possesses considerable anxiolytic activity, although it is a less potent antidepressant than imipramine or amitriptyline.
Viloxazine: This is a bicyclic antidepressant which was by chance developed from a series of beta-blockers.
Maprotiline: Its pharmacological and its properties resemble the tricyclics.
Trazodone: Trazodone is chemically unrelated to tricyclics, tetracyclics, or MAOIs. Its efficacy is comparable to that of tricyclics. Trazodone selective interferes with the uptake of serotonin by nerve endings.

Monoamine Oxidase Inhibitors (MAOIs): 
The MAOIs are generally less effective and more toxic than the tricyclics, their use is limited to depressive disorders refractory to tricyclic agents. These agents do not cause anticholinergic effects associated with the tricydics.
Currently, the most commonly used% MAOIs for depression are pheneizine and tranylcypromin.
Combination of Antidepressants: A tricyclic-MAOI combination may be used with advantage in relieving certain depressions that are unresponsive to conventional therapy. Both the agents ideally should be started at the same time, or the tricyclic first followed by the MAOI. In any case the MAOI should never be started before the tricycic antidepressant.

Lithium carbonate
Lithium counteracts mood changes, without producing sedation, and is considered to be the only specific antimaniac drug for the prophylaxis and treatment of manic-depressive disorders. Lithium has a narrow margin of safety, and should therefore not be prescribed unless facilities for monitoring plasma concentrations are available.