A 26-year-old man is brought to the emergency department due to hallucinations. The patient's mother reports that he was acting normally until a few hours ago when he started hallucinating that dogs were chasing him. She states that the patient has a history of schizoaffective disorder that was difficult to treat and is currently taking clozapine and doxepin; however, she is worried about his mental health because he broke up with his partner yesterday. Temperature is 38.3 C (100.9 F), blood pressure is 140/80 mm Hg, pulse is 145/min, and respirations are 24/min. Oxygen saturation is 97% on room air. The patient is delirious and actively hallucinating. His pupils are 6 mm and nonreactive. No murmurs or gallops are present on auscultation of the heart. Muscle tone and reflexes are normal. What is the best next step in management?

Question

A 26-year-old man is brought to the emergency department due to hallucinations.  The patient's mother reports that he was acting normally until a few hours ago when he started hallucinating that dogs were chasing him.  She states that the patient has a history of schizoaffective disorder that was difficult to treat and is currently taking clozapine and doxepin; however, she is worried about his mental health because he broke up with his partner yesterday.  Temperature is 38.3 C (100.9 F), blood pressure is 140/80 mm Hg, pulse is 145/min, and respirations are 24/min.  Oxygen saturation is 97% on room air.  The patient is delirious and actively hallucinating.  His pupils are 6 mm and nonreactive.  No murmurs or gallops are present on auscultation of the heart.  Muscle tone and reflexes are normal.  What is the best next step in management?

Quizplus · Accepted Answer

11ec25c8_d767_7108_bc81_f762495445ff_MD0003_00 This patient with underlying mental illness (schizoaffective disorder) and a recent stressful event (romantic breakup) has symptoms consistent with anticholinergic toxicity (eg, hallucinations, mydriasis, hyperthermia, tachycardia) likely due to an overdose of either one or both of his medications. Doxepin, a tricyclic antidepressant (TCA), and clozapine, a second-generation antipsychotic, along with many other medications, can cause anticholinergic toxicity when taken in combination or in excess. anticholinergic toxicity medications Anticholinergic toxicity should be considered in patients with altered mental status, tachycardia, and hyperthermia, especially those taking multiple psychiatric medications with anticholinergic properties (such as this man). There are no confirmatory laboratory tests. Serum drug levels of most anticholinergic medications are not typically available on an emergency basis and results are not clinically relevant; patients should be treated based on their clinical presentation. An electrocardiogram to evaluate for possible QRS interval or QTc prolongation should be performed in all patients with anticholinergic toxicity because TCAs may cause QRS interval prolongation that can progress to ventricular arrhythmia and cardiac arrest. Other medications with anticholinergic properties are associated with cardiac toxicity, and certain antihistamines (also anticholinergic agents) have also been shown to prolong the QTc. (Choice A) The dopamine agonist bromocriptine is used to treat neuroleptic malignant syndrome (NMS). NMS is a life-threatening reaction to an antipsychotic (eg, clozapine). It is characterized by the tetrad of muscular rigidity, autonomic instability, altered mental status, and hyperthermia. This patient's muscle tone is normal, making NMS unlikely. (Choice B) Haloperidol is a butyrophenone antipsychotic used to treat agitated delirium. Butyrophenones and phenothiazines possess anticholinergic properties and may exacerbate symptoms. They should not be administered to patients suspected of having anticholinergic toxicity. (Choice D) An electroencephalogram (EEG) can identify ongoing subclinical seizure activity that can be confused with other neurologic conditions. However, seizures typically have an abrupt onset and evolve over seconds to minutes. In addition, autonomic dysfunction (eg, hyperthermia, hypertension) and hallucinations are more suggestive of anticholinergic toxicity than a postictal state. Educational objective: Patients suspected of anticholinergic toxicity (eg, altered mental status, tachycardia, dry skin, mydriasis, urinary retention) should have an electrocardiogram performed early in their evaluation because medications with anticholinergic properties (eg, tricyclic antidepressants) may also cause QRS interval or QTc prolongation, and other arrhythmias. References: Anticholinergic toxicity. (http://www.ncbi.nlm.nih.gov/pubmed/30521219) Pharmacological management of anticholinergic delirium - theory, evidence and practice. (http://www.ncbi.nlm.nih.gov/pubmed/26589572)

A 26-Year-Old Man Is Brought to the Emergency Department Due