First Glance

Tricyclic antidepressants for adults should be given preferably as a single dose.

Tricyclic antidepressants can be started with a daily dose of 50-75 mg and the dose can be increased to 100-150 mg daily after a week.

Antidepressants usually take 10-14 days to produce their antidepressant effect, though effects on sleep , anxiety and restlessness may occur after a few hours.

The same tricyclic antidepressants should be continued for at least six weeks before being considered as ineffective for that person. Frequent change of antidepdressant does not help.

The advantages of giving a single bed-time dosage (late evening 7-8 p.m.) are many, such as :

• Compliance is better,
• The beneficial effect lasts the entire day following administration, due to adequate half-life,
• Anticholinergic and other side-effects, which usually occur a few hours after ingestion, pass off during sleep, without causing problems to the patient,
• The sedative effect can be taken advantage of since it would help the depressed patient to sleep and avoid need of an additional sedative.

The depressed patient and the family members should be educated about the use of antidepressants. The appropriate time for producing antidepressant effects should be explained. Common side-effects should be explained and also the fact that most side-effects would wear off in due course of time. They should also be educated about how to cope with the common side-effects like dryness of mouth (use frequent sips of water, chew gum or mint), orthostatic hypotension (by gradual change of posture) and constipation (by diet, and use of isabgol husk).

Common side-effects of antidepressants

Tricyclic antidepressants

• Drowsiness
• Anticholinergic effects
  • Dry mouth
  • Blurring of vision
  • Orthostatic/ postural hypotension
  • Urinary retention
  • Paralytic ileus
  • Constipation
  • Precipitation of glaucoma
  • Central anticholinergic syndrome
• Rarely, sweating, parkinsonism, oedema
• Cardiovascular-nonspecific ECG changes
• Mania

Tetracyclic antidepressants

• Drowsiness
• Anticholinergic side-effects are uncommon
• Increased appetite-effects also uncommon
• Blood dyscrasias, rare

Serotonin reuptake inhibitors

• Nausea
• Nervousness
• Insomnia
• Weight loss
• Rash, urticaria

Phenyl-piperazine derivatives like trazodone

• Drowsiness
• Insomnia, rarely
• GIT upset and dizziness, rarely
• CVS and anticholinergic side-effects extremely rare
• Priapism
• Rarely mania

How long to give antidepressants?

Duration of antidepressant treatment

The average duration of a depressive episode is 8-12 months and antidepressant medications should be given for this period. Alternatively, once the depressive symptoms have ameliorated, antidepressants should be gradually tapered and a maintenance dose of 75-100 mg should be given for another 6 months.

If antidepressants are stopped as soon as depression has lifted, the chances of relapse are high.