Antidepressant drugs: disturbing and potentially dangerous adverse effects

Adverse effects associated with antidepressant drug therapy rarely cause significant morbidity or mortality. Nevertheless, the successful management of patients with depression requires recognition of potential adverse effects that have serious consequences, which include the discontinuation of otherwise effective therapy. The aim of this overview is to highlight the more common and potentially deleterious adverse effects of both older and newer classes of antidepressant drugs. Major adverse effects attributed to the tricyclic antidepressant drugs (TCAs) include conduction defects and lethal overdose. Most worrisome with the selective serotonin reuptake inhibitor drugs (SSRIs) is the serotonin syndrome. Although rare, this syndrome can be insidious and lethal. Recent trends toward the use of medication combinations and augmentation therapies significantly enhance the risk of serotonin syndrome. Cognitive impairment also may occur, especially with the TCAs. Apathy is occasionally a problem with SSRI therapy. The syndrome of inappropriate antidiuretic hormone (SIADH) has been reported with most antidepressant drugs but appears to be more common with serotonergic agents and in elderly patients. Although seizures are uncommon in patients receiving antidepressant therapy, the risk must be understood by both the patient and the clinician. Adverse effects related to sexual function are common, especially with TCAs, SSRIs, and venlafaxine. Sexual dysfunction often leads to noncompliance and self-discontinuation of therapy. Sleep disturbances are common in patients with depression, and recent data illustrate how crucial sleep regulation is to mood. Antidepressant drugs vary in their sleep effects. Although antidepressant drugs can cause a variety of adverse effects, these drugs save lives and their benefits far exceed their risks.