MANAGEMENT OF ANTIDEPRESSANTS IN OVERDOSE

Antidepressant drugs are commonly used in attempted suicide. While the newer selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibi tor antidepressants induce relatively minor effects when taken in over dose, the first generation tricyclics and second generation tri- and t etracyclic antidepressants cause life-threatening effects in overdose and, as a result, are the major cause of overdose deaths due to prescr iption drugs. Initial management should ensure a clear airway and adeq uate breathing and circulation. Investigations such as assessment of e lectrolyte, blood glucose and creatine kinase levels and arterial bloo d gases should be preformed. Since overdosage with many antidepressant s can cause serious cardiovascular complications, electrocardiographic al, assessment is also an important aspect of general management. In p atients who have taken an overdose of first generation tricyclics or s econd generation tri- and tetracyclic antidepressants, the principles of management are to reduce absorbtion (with charcoal), maintain oxyge nation, optimise perfusion (with intravenous fluids and inotropic drug s) and use systemic alkalinisation to treat major cardiovascular arrhy thmias. Appropriate treatment of cerebral symptoms (coma, seizures, my oclonus) may also be required. Although serotonin reuptake inhibitors are much less toxic when taken in overdose than other antidepressants, the management principles remain the same. Overdose with monoamine ox idase inhibitors produces characteristic abnormalities (hypertension, muscular rigidity, hyperthermia) that need specific treatment. All pat ients presenting with an overdose of an antidepressant should receive psychiatric and social assessment before discharge.