| The pharmacotherapy of depression has advanced considerably in the past few years. A decade before we had only a couple of tricyclic antidepressants at our perusal. But now we have about fifteen antidepressants available in India and another fifteen in international market; many of which are likely to be available in India in near future.
Q. What are the common clinical guidelines for use of antidepressants?
- Start with a small dose.
- Gradually increase to minimum effective or maximum tolerable dose over a period of next one to two weeks.
- Inform the patient about the common expected side effects. Dryness of mouth, giddiness while getting up, with tricyclic antidepressants, gastrointestinal and CNS side effects with SSRIs.
- Inform about the delayed onset of therapeutic action.
The therapeutic benefit may be observed after a period of about three weeks.
- Continue the treatment for a period of 6-8 months.
Earlier discontinuation may cause resurgence of symptoms.
- Gradually reduce the dose and discontinue after 6-8 months.
Sudden discontinuation may cause withdrawal symptoms like nausea, vomiting restlessness, insomnia etc.
Q. What are the limitations of conventional antidepressants?
Ans. The conventional antidepressants like imipramine and amitriptyline are still very useful in the treatment of depression in young adults. But in elderly persons and persons having concomitant medical and surgical problems,they need to be used with caution.
They may cause anticholinergic side effects like dryness of mouth, constipation and sexual dysfunction. In elderly patients or medically compromised patients they may cause bowel and bladder paralysis or aggravation of acute angle glaucoma. They may also cause postural hypotension and at higher dose cardiac arrhythmias.
Q. In what way are newer antidepressants better than conventional ones?
Ans. As far as the therapeutic efficacy of the antidepressants is concerned, almost all the antidepressants have more or less equal therapeutic efficacy. But, clinically it is often noticed that a patient who doesn't respond to treatment with one antidepressant may respond to another antidepressant.
As far as the side effect profile is concerned, many of the newer antidepressants have better side effect profile in terms of anticholinergic side effects, postural hypotension and cardiotoxicity. (example, dothiepin, fluoxetin, amineptine etc). As a result they are well tolerated and can be safely administered in elderly patients as well as in patients with concomitant medical or surgical problems.
Q. Which are the antidepressants available in India?
Ans. The following antidepressants are available in India :
| Imipramine |
Doxepin |
Trazodone |
Fluoxetine |
| Trimipramine |
Dothiepin |
Amineptine |
Sertraline |
| Clomipramine |
Amoxapine |
Tianeptine |
|
| Amitriptyline |
Mianserin |
Lithium |
|
| Nortriptyline |
|
|
|
Q. How does one choose an antidepressant for a particular individual?
Ans. In order to choose appropriate antidepressant for an individual patient, the following aspects may be considered :
a) Past history or family history
If the patient or his family members have shown a good response to a particular antidepressant in the past, it is very likely that he will respond well to the same antidepressant once again.
b) Target symptoms
In a patient with severe insomnia, an antidepressant like amitriptyline, doxepin, dothiepin, or trazodone which have good sedative effect may be preferred.
c) Associated symptoms
Frequently symptoms of anxiety are associated with depression. In such cases one may either add an antianxiety drug like chlordiazepoxide for a short duration or choose a drug like dothiepin, doxepin, or tianeptine which will take care of anxiety symptoms as well.
Chronic daily headache, migraine or other aches and pains associated with depression may respond well to amitriptyline.
Heat burns, gastritis, indigestion, bloating sensation are common in patients of depression. Trimipramine and doxepin block histamine-2 receptors and so may be useful in patients of depression with gastrointestinal symptoms.
Clomipramine and fluoxetine have been found to be particularly useful in cases of obsessive compulsive disorders(OCD). For depression associated with OCD, these drugs may be used.
Amoxapine has clinically significant dopamine receptor blocking activity. This makes it therapeutically useful for depression with psychotic features. Use of amoxapine may obviate the need for addition of separate antipsychotic for psychotic features.
When there is a past history of mania or hypomania as in the case of bipolar disorder or history suggestive of personality disorder (borderline personality disorder or antisocial personality disorder), treatment with lithium may be considered for the present depressive episode.
d) Side effect profile
Among the tricyclic antidepressants dothiepin, nortriptyline are associated with the least postural hypotension and so may be preferred in patients who are prone to this side effect.
Trazodone is not associated with the usual anticholinergic adverse effects, such as urinary retention and constipation.
Dothiepin, mianserin, fluoxetine and tianeptine are less cardiotoxic and may be preferred in patients with cardiac problems. Fluoxetine doesn't cause weight gain like other antidepressants.
Q. What happens when a patient takes an overdose of antidepressants?
Ans. Overdose attempts with tricyclic antidepressants are serious and can be fatal. They may cause respiratory depression and cardiac arrhythmias which may be fatal.Overdose of other antidepressants may also be fatal especially when taken along with other psychotropic drugs or along with alcohol.
Q. What is the addiction potential for antidepressants?
Ans. Antidepressants do not give immediate gratification like alcohol and other drugs and so patients do not develop dependence on it. The exception to this rule is alprazolam which is widely used as a sedative-hypnotic drug, antipanic drug. Patients may develop physiological and psychological dependence on alprazolam if due precautions are not taken.
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