Due to a large number of side-effects caused by the tricyclic antidepressants and the monoamine oxidase inhibitors, efforts have been made by pharmaceutical research groups to bring out newer and safer drugs.



Selective Serotonin Reuptake Inhibitors (SSRIs)

The major drawback of conventional tricyclic antidepressants are unacceptable effects on heart (fall in BP, rhythm disturbances) anticholinergic and neurological adverse effects. Low safety margin, as fatalities are common. Slow onset of action. Propensity to precipitate fits; Sedation; Incomplete/poor response in some patients. Advent of SSRIs in 1980 have overcome above limitations to a great extent. SSRIs are becoming preferred drugs for th.el treatment of endogenous depression because of their merits, which are:

Quick onset of action.

Little or no sedation.

No interference with mental functions.

No postural fall in blood pressure so appropriate in elderly.

No precipitation of convulsions.

Little chance of overdose and heart rhythm disturbance.

Antidepressant efficacy equal to tricyclics.

Utility in anxiety, phobia and obsessive compulsive neurosis.

Adverse Effects: Nausea, interference with ejaculation, orgasm nervousness, restlessness, insomnia, loss of appetite, mild abnormal movements, headache and diarrhoea may occur. Sometimes discontinuation of SSRIs result in bowel upset, pins-needles sensations, bodyache and sleep disturbance. Importantly, these drugs may adversely interact with antihistaminics, antipsychotics, propranolol, carbamazepine and diazepam. Therefore, patients on such medications should have appropriate dose adjustments.

St John's Wart (Hypericin, Hylax)

Hypericin is an active ingredient of aerial parts of St John's Wart. It is an effective mood elevator and antidepressant in mild to moderate depression in a dose of 1 capsule three times twice a day. It is particularly used when depression is due to a serious medical illness, concurrent medications (amitryptyline, anti HIV drugs, theophylline and warfarin) interact with it.

Mono-amine Oxidase Inhibitors (MAO-Is)

These are older drugs effective in depression but show a lot of adverse interactions with drugs and food . The cheese reaction occurs when foods/beverages such as cheese, bean, red wine, over ripe fruits, broad beans, yeast and soya sauce (all contain a chemical tyramine) are patients on MAO-Is.