Tricyclic Antidepressant - Side Effects

Side Effects

Many side effects may be related to the antimuscarinic properties of the TCAs. Such side effects are relatively common and may include dry mouth, dry nose, blurry vision, lowered gastrointestinal motility or constipation, urinary retention, cognitive and/or memory impairment, and increased body temperature.

Other side effects may include drowsiness, anxiety, emotional blunting (apathy/anhedonia), confusion, restlessness, dizziness, akathisia, hypersensitivity, changes in appetite and weight, sweating, sexual dysfunction, muscle twitches, weakness, nausea and vomiting, hypotension, tachycardia, and rarely, irregular heart rhythms. Twitching, hallucinations, delirium and coma are also some of the toxic effects caused by overdose. Rhabdomyolysis or muscle breakdown has been rarely reported with this class of drugs as well.

Tolerance to these adverse effects of these drugs often develops if treatment is continued. Side effects may also be less troublesome if treatment is initiated with low doses and then gradually increased, although this may also delay the beneficial effects.

TCAs can behave like class 1A Antiarrhythmics, as such, they can theoretically terminate ventricular fibrillation, decrease cardiac contractility and increase collateral blood circulation to ischemic heart muscle. Naturally, in overdose, they can be cardiotoxic, prolonging heart rhythms and increasing myocardial irritability.