Antidepressants are a type of medication prescribed to treat depression and other mental health conditions, such as anxiety or personality disorders. There are four different classes of antidepressants approved by the U.S. Food and Drug Administration: monoamine oxidase inhibitors, cyclic antidepressants, selective serotonin reuptake inhibitors and atypical antidepressants. If you or a loved one takes this type of medication, it is important to be aware of the signs of antidepressant toxicity. If any of these signs develop, seek emergency medical care to prevent life-threatening complications.
Monoamine Oxidase Inhibitors
Monoamine oxidase inhibitors (MAOIs), such as phenlzine or tranylcypromine, may cause a number of symptoms if toxic levels of this medication are ingested. Symptoms following an MAOI overdose may take 6 to 24 hours to develop in some people. A review published in "Clinical Pediatric Emergency Medicine" in 2008 reported that the most common signs of MAOI toxicity include headache, anxiety, restlessness or flushing of the skin. Cardiovascular complications including elevated blood pressure (hypertension) or an abnormally rapid heartbeat (tachycardia). A person experiencing MAOI toxicity may appear severely intoxicated or delirious. Seizures, bleeding of the brain or an abnormally high body temperature (hyperthermia) might also be indicative of MAOI toxicity.
Cyclic Antidepressants
Cyclic antidepressants (CAs) or tricyclic antidepressants (TCAs), such as amitriptyline or doxepin, can be toxic when ingested in amounts that exceed the prescribed dose. Toxic levels of CAs or TCAs may cause damage to the central nervous system, which can cause delirium, fatigue or coma. Cardiovascular issues may also develop and can include decreased blood pressure (hypotension) or an abnormally rapid heartbeat. Severe seizures can also be a sign of CA or TCA toxicity in certain people.
Selective Serotonin Reuptake Inhibitors
Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine or sertraline, may cause a number of symptoms to develop if taken at toxic levels. Common signs of SSRI toxicity include dizziness, nausea, vomiting or blurred vision. Toxic levels of SSRIs within the blood may cause depression of the central nervous system, which can affect cognitive and physical behavior. Someone who has ingested high levels of SSRIs may appear confused or be unable to speak clearly or walk normally. Though rare, seizures have also been reported in patients who experience SSRI toxicity. Some people might develop a condition called serotonin syndrome, which can cause diarrhea, headache, shivering, dilated pupils, confusion, restlessness or loss of muscle coordination.
Atypical Antidepressants
Atypical antidepressants, such as venlafaxine, can cause toxicity symptoms to occur if this medication is taken in excess. Toxic levels of atypical antidepressants within the body may cause seizures to occur in certain people. An abnormally high body temperature may also be a sign of atypical antidepressant toxicity. Depression of the central nervous system, which may lead to cognitive, language or fine motor skill deficiencies, may be indicative of an overdose of this medication. Cardiovascular complications, including low blood pressure or an abnormally elevated heart rate might also be a sign of atypical antidepressant toxicity.
References
- "Clinical Pediatric Emergency Medicine"; An Update on Antidepressant Toxicity - An Evolution of Unique Toxicities to Master; Dr. EL Liebelt; 2008
- "Emergency Medicine Journal"; Tricyclic antidepressant overdose: a review; GW Kerr, et. al.; 2001
- "Emergency Medicine Journal"; Review of prehospital sodiium bicarbonate use for cyclic antidepressant overdose; T Calkins, et. al.; 2003
