Edit concept Question Editor Create issue ticket

Antidepressant Toxicity

Antidepressants Toxicity


  • If suicidal ideation is present, evaluation for admission to a psychiatric facility is mandatory.[emedicine.medscape.com]
  • This case presents comatose and tricyclic antidepressant overdose. It includes a full discussion and explanation with an emphasis on the mechanism of coma in this particular case, in addition to subsequent management and expected outcome.[oxfordmedicine.com]
  • Additionally, you may go back to previous EM:RAP episodes and redeem CME (any episode Jan 2015 to the present, 6 hours per month). On EM:RAP we try to make make the process simple and the question sets are quite reasonable.[emrap.org]
  • Physical Exam Anticholinergic Toxidrome may be present Physical exam findings include: mydriasis, dry and hot skin, urinary and bowel retention, hyperthermia, xerostomia, tachycardia and AMS (disorientation, confusion) Pulmonary: Coarse breath sounds[coreem.net]
  • Tachycardia is often present as a result of the anticholinergic effects of TCAs or as a reflex response to alpha1-blockade mediated hypotension. Bradycardia in the context of a massive TCA overdose is generally a pre-terminal event.[lifeinthefastlane.com]
  • The effect of 5-hydroxytryptamine 3A and 3B receptor genes on nausea induced by paroxetine . Pharmacogenomics J 2006; 6 : 351–356. 39. Gerstenberg G , Aoshima T , Fukasawa T , Yoshida K , Takahashi H , Higuchi H et al .[nature.com]
  • In an overdose situation, they can potentially cause: Agitation Fainting Nausea Vomiting Diarrhea Dizziness Fever Seizures Tricyclic antidepressants Tricyclics include drugs like Tofranil, Norpramin, and Surmontil.[amphetamines.com]
  • This can include insomnia and symptoms similar to flu like a headache and nausea. Constipation. Trouble urinating. Dry mouth. Weight gain. Possible sexual dysfunction. Blurred vision. Abdominal pain. Anxiety.[medtox.org.uk]
  • Symptoms may include: Confusion Agitation or restlessness Dilated pupils Headache Changes in blood pressure and/or temperature Nausea and/or vomiting Diarrhea Rapid heart rate Tremor Loss of muscle coordination or twitching muscles Shivering and goose[webmd.com]
  • Risk Assessment Symptoms in overdose are typically mild and are manifestations of serotonin excess, including nausea, vomiting and dizziness. Uncommonly serotonin toxicity can occur and should be actively looked for.[emergpa.net]
Absent Bowel Sounds
  • bowel sounds, suprapubic fullness secondary to urinary retention Neuro: Initially altered mental status including delirium and agitation followed by lethargy and stupor, seizure activity, myoclonus, dystonia, akathisia, rigidity, myoclonus Skin: dry,[coreem.net]
  • bowel sounds High fever, or inability to regulate temperature Anhidrosis Delirium Metabolic features Metabolic acidosis Respiratory acidosis Management of tricyclic overdose Decontamination Activated charcoal reduces absorption and can be used in single[derangedphysiology.com]
Abdominal Pain
  • Abdominal pain. Anxiety. The side-effects of antidepressant medication will vary according to which type you are using.[medtox.org.uk]
  • […] bowel sounds, suprapubic fullness secondary to urinary retention Neuro: Initially altered mental status including delirium and agitation followed by lethargy and stupor, seizure activity, myoclonus, dystonia, akathisia, rigidity, myoclonus Skin: dry, flushed[coreem.net]
  • […] alpha-blocking effects and myocardial depression) broad complex tacydysrrhythmia broad complex bradycardia occurs pre-arrest anticholinergic effects may occur on present or may be delayed and prolonged agitation, restlessness, delirium mydriasis dry, warm flushed[lifeinthefastlane.com]
  • Cardiovascular effects most commonly include sinus tachycardia, flushing, hypertension, and in rare cases, hypotension.[emedicine.medscape.com]
  • Jason Sims, PharmD, for their critical review and suggestions. Williams & Wilkins 1997. All Rights Reserved.[journals.lww.com]
  • The increasing use of MAO-A inhibitors and SSRIs in the treatment of depression suggests that careful clinical observation is required when combination overdoses are suspected.[ncbi.nlm.nih.gov]
  • This study does suggest that in overdose the dose is an important association, with higher doses taken in serotonin toxicity patients.[nature.com]
  • However, about 88% of the poison control directors in the United States use a QRS of 100 milliseconds or greater as the threshold for use of intravenous sodium bicarbonate. [15] Evidence suggests the reversal of toxic effects of CA (eg, QRS prolongation[emedicine.medscape.com]
  • The position statement of the American College of Medical Toxicology regarding lipid emulsion therapy suggests a maximum of 2 full doses of 20% lipid.[emergencymedicinecases.com]
  • (inducible or sustained ankle clonus, ocular clonus), agitation/anxiety, hypertonia and hyperthermia (temperature 38  C)).[nature.com]
  • Inducible or spontaneous clonus of the lower extremities is very common with serotonin syndrome. Prolongation of the QT interval can be observed following SSRI overdose, especially in cases involving citalopram or escitalopram.[cancertherapyadvisor.com]


Right Axis Deviation
  • Specific Findings Poorly Diagnostic Findings Terminal QRS Axis 33% 71% Right axis deviation of 120-270 degrees in the terminal 40ms frontal plane QRS vector for ventricular arrhythmias Study: J Toxicol Clin Toxicol. 2004;42(6):877-88.[getthediagnosis.org]
  • Evaluating the relationship between ingested TCA dosage and electrocardiographic findings (duration of QRS, QT and PR intervals, the amplitude of R wave in lead aVR and right axis deviation) in both study groups, demonstrated that there was a strong relationship[scopemed.org]
  • The important ECG findings suggestive of TCA toxicity are: QRS widening ( 100 ms) and right axis deviation of the terminal QRS In combination, these findings are almost pathognomic of sodium channel blockade: Right axis deviation of the terminal QRS is[lifeinthefastlane.com]
  • axis deviation of the terminal QRS Heart block Vasodilation Hypotension Arrhythmias, including VF and torsade Central nervous system features Drowsiness Coma Seizures Pyramidal signs and rigidity Ophthalmoplegia Anticholinergic features Dry mouth Blurred[derangedphysiology.com]
  • Wide complex tachycardia ( 120ms) with a right axis deviation Tall R wave in lead aVR QTc prolongation The combination of these ECG findings is highly suspicious for a Sodium Chanel Blocker overdose, of which TCA is a classic example.[emergencymedicinecases.com]
Epileptiform Activity
  • Activity, Epilepsy, Seizures, REM Sleep/Memory/EEG Problems, Sleepwalking Go to: Hypoglycemia (low blood sugar), Hyperglycemia (high blood sugar, Diabetes) Go to: Urinary Incontinence, Dermatologic (Skin) Problems, Ocular (Eyes) Disturbances Go to: Pain[antidepressantsfacts.com]


  • The treatment of an asymptomatic patient with a history of CA ingestion is mainly supportive therapy.[emedicine.medscape.com]
  • […] outcomes following treatment with clozapine, which modifies serotonergic activity in the brain, 19 and the 5-HT 2A polymorphism has also been investigated for a possible role in antidepressant treatment outcomes, but results to date have shown only marginal[nature.com]
  • Sodium bicarbonate is used for treatment of these complications which may have some effect on serum sodium levels.[advbiores.net]
  • The increasing use of MAO-A inhibitors and SSRIs in the treatment of depression suggests that careful clinical observation is required when combination overdoses are suspected.[ncbi.nlm.nih.gov]
  • Does drug treatment reduce the risk of further self-harm or suicide? . BJPsych Advances, Vol. 22, Issue. 1, p. 3.[cambridge.org]


  • Prognosis In general, patients who arrive alive at health care facilities have a very good prognosis. Most deaths from these agents occur in the prehospital period. Thus, if an individual survives to hospital admission, the prognosis is quite good.[cancertherapyadvisor.com]
  • Antidepressant serum levels show no correlation to severity or prognosis of intoxication. Lactate production is increased due to respiratory depression and mixed acidosis.[pharmacytimes.com]


  • Use of over-the-counter medications or dietary supplements in addition to prescribed serotonergic medications is also an important etiology.[emedicine.medscape.com]
  • Diagnostic approach History is the essential in determining the etiology of the symptoms. Certainly aggressive supportive care is key, and patient care should not be delayed while trying to obtain a history.[cancertherapyadvisor.com]


  • He has since completed further training in emergency medicine, clinical toxicology, clinical epidemiology and health professional education.[lifeinthefastlane.com]
  • Tricyclic antidepressants are highly protein bound and have a large volume of distribution ; therefore removal of these compounds from the blood with hemodialysis , hemoperfusion or other techniques are unlikely to be of any significant benefit. [12] Epidemiology[en.wikipedia.org]
  • Epidemiology As the prevalence of psychiatric disorders increases in Western society, there is a corresponding increase in the number of prescriptions written for these medications. Overdose of psychiatric medications is quite common.[cancertherapyadvisor.com]
Sex distribution
Age distribution


  • The exact pathophysiology of serotonin toxicity is still not fully understood, except that it occurs with an excess of serotonin in the central nervous system.[nature.com]
  • […] toxic dose. [7] Factors that increase the risk of toxicity include advancing age, cardiac status, and concomitant use of other drugs. [8] However, serum drug levels are not useful for evaluating risk of arrhythmia or seizure in tricyclic overdose. [9] Pathophysiology[en.wikipedia.org]
  • Pathophysiology Antidepressants Antidepressants work by different mechanisms, but ultimately most attempt to correct an imbalance of the dopaminergic, noradrenergic, and serotonergic systems.[cancertherapyadvisor.com]


  • Restriction of access to methods of suicide as a means of suicide prevention . In Prevention and Treatment of Suicidal Behaviour: From Science to Practice : 279–91.[cambridge.org]
  • Indications for sodium bicarbonate in tricyclic antidepressant overdose: Severe cardiotoxicity cardiac arrest ventricular dysrhythmias hypotension resistant to fluid challenge Consider for prevention of severe cardiotoxicity resulting from: seizure –[lifeinthefastlane.com]
  • This "hyperserotonergic" toxic condition requires heightened clinical awareness in order to prevent, recognize, and treat the condition promptly.[antidepressantsfacts.com]
  • This may prevent hyperthermia and rhabdomyolysis. The use of hypertonic saline in CA toxicity remains controversial.[emedicine.medscape.com]
  • If you or someone you know is considering suicide, get help from a crisis or suicide prevention hotline. Try the National Suicide Prevention Lifeline at 800-273-8255. If you suspect an overdose has occurred, seek emergency medical care right away.[healthline.com]

Ask Question

5000 Characters left Format the text using: # Heading, **bold**, _italic_. HTML code is not allowed.
By publishing this question you agree to the TOS and Privacy policy.
• Use a precise title for your question.
• Ask a specific question and provide age, sex, symptoms, type and duration of treatment.
• Respect your own and other people's privacy, never post full names or contact information.
• Inappropriate questions will be deleted.
• In urgent cases contact a physician, visit a hospital or call an emergency service!