Antipsychotic toxicity: Difference between revisions
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== | ==Workup== | ||
* POC Glucose | |||
* ECG (QT interval) | |||
* Co-ingestions: serum acetaminophen, salicylate, EtOH level, other known drug levels | |||
* Urine toxicology screen | |||
* Chemistry (metabolic acidosis, electrolytes, renal function) | |||
* LFT (hepatotoxicity) | |||
* CK (rhabdomyolysis) | |||
* Serum osmolarity (osmolar gap) | |||
* ABG (carboxyhemoglobin, methemoglobin) | |||
==Treatment== | ==Treatment== | ||
Revision as of 21:03, 3 June 2016
Background
- Isolated overdose of antipsychotics is rarely fatal
- Toxicity results in blockade of some or all of the following receptors:
- Dopamine - extrapyramidal symptoms
- Alpha-1 - orthostatic hypotension, reflex tachycardia
- Muscarinic - anticholinergic symptoms
- Histamine - sedation
Clinical Features
- Extrapyramidal
- Acute dystonia
- Tongue protrusion, facial grimacing, trismus, oculogyric crisis
- Akathisia
- Acute dystonia
- CNS
- Lethargy, ataxia, dyarthria, confusion, coma
- Seizure (1%)
- Anticholinergic Effects
- Tachycardia, dry mucous membranes, dry skin, decreased bowel sounds, delirium
- ECG changes
- Sinus tachycardia
- QT prolongation
Differential Diagnosis
Anticholinergic toxicity Causes
- Medications[1]
- Atropine
- Antihistamines
- Antidepressants
- Antipsychotics
- Muscle relaxants
- Anti-Parkinsonians
- Plants
- Jimson weed (Devil's trumpet)
- Amanita mushroom
Workup
- POC Glucose
- ECG (QT interval)
- Co-ingestions: serum acetaminophen, salicylate, EtOH level, other known drug levels
- Urine toxicology screen
- Chemistry (metabolic acidosis, electrolytes, renal function)
- LFT (hepatotoxicity)
- CK (rhabdomyolysis)
- Serum osmolarity (osmolar gap)
- ABG (carboxyhemoglobin, methemoglobin)
Treatment
- Supportive
- Hypotension
- QT prolongation
- Treat all pts w/ QTc >500ms w/ magnesium 2-4gm IV over 10min
- Extrapyramidal
- Diphenhydramine 25-50mg IV/IM OR benztropine 1-2mg IV/IM
- Oral therapy with either of above meds should be continued for 2 weeks
Disposition
- Consider discharge after 6hr as long as there are all of the following:
- No mental status changes
- Normal HR/BP
- No orthostatic hypotension
- Normal QT interval
See Also
- Neuroleptic Malignant Syndrome (NMS)
- Tardive dyskinesia
- Beta-Blocker Toxicity
- Calcium Channel Blocker Toxicity
References
- ↑ Dawson AH, Buckley NA. Pharmacological management of anticholinergic delirium – theory, evidence and practice. Br J Clin Pharmacol. 2015;81(3):516-24.