Tricyclic Antidepressants (TCAs) (cont.)

Are there differences among tricyclic antidepressants?

Tricyclic antidepressants differ in their relative effects on serotonin, norepinephrine, and acetylcholine. The differences are reflected in how the tricyclic antidepressants are used and, most importantly, their propensity to cause certain side effects. For instance, amitriptyline (Elavil) causes more sedation, dry mouth, and constipation than other tricyclic antidepressants.

What are the side effects of tricyclic antidepressants?

Tricyclic antidepressants may cause:

• blurred vision,
• dry mouth,
• constipation,
• weight gain or loss,
• low blood pressure on standing,
• rash,
• hives, and
• increased heart rate.

Tricyclic antidepressants should be used cautiously in patients with seizures since they can increase the risk of seizures.

Tricyclic antidepressants may worsen urinary retention (difficulty urinating) and narrow angle glaucoma. Abnormal heart rhythms and sexual dysfunction have also been associated with tricyclic antidepressants.

If tricyclic antidepressants are discontinued abruptly, withdrawal symptoms (for example, dizziness, headache, nausea, and restlessness) may occur. Withdrawal symptoms may occur when even a few doses are missed. Therefore, the dose of antidepressant should be reduced gradually when therapy is discontinued.

Antidepressants increased the risk of suicidal thinking and behavior in short-term studies in children and adolescents with depression and other psychiatric disorders. Anyone considering the use of any antidepressant in a child or adolescent must balance this risk with the clinical need. Patients who are started on therapy should be closely observed for clinical worsening, suicidal thinking or behavior, and unusual changes in behavior.