The objective of this guideline is to assist poison center personnel in the appropriate out-of-hospital triage and out-of-hospital management of patients with suspected acute ingestions of atypical antipsychotic medications by 1) describing the process by which an ingestion of an atypical antipsychotic medication might be evaluated, 2) identifying the key decision elements in managing cases of atypical antipsychotic medication ingestion, 3) providing clear and practical recommendations that reflect the current state of knowledge, and 4) identifying needs for research. This guideline applies to ingestion of atypical antipsychotic medications alone. Co-ingestion of additional substances could require different referral and management recommendations depending on the combined toxicities of the substances. This guideline is based on an assessment of current scientific and clinical information. The expert consensus panel recognizes that specific patient care decisions might be at variance with this guideline and are the prerogative of the patient and the health professionals providing care, considering all of the circumstances involved. This guideline does not substitute for clinical judgment. The grade of recommendation is in parentheses. 1) Patients with stated or suspected self-harm or the recipient of a potentially malicious administration of an atypical antipsychotic medication should be referred to an emergency department immediately. This activity should be guided by local poison center procedures. In general, this should occur regardless of the dose reported (Grade D). 2) Patients without evidence of self-harm should have further evaluation, including determination of the precise dose ingested, presence of signs or symptoms of toxicity, history of other medical conditions, and the presence of co-ingestants (Grade C). 3) Asymptomatic patients without evidence of attempted self-harm are unlikely to develop symptoms if the interval between the ingestion and the call is greater than 6 hours. These patients do not need referral and should receive follow-up based on local poison center protocols (Grade C). 4) All patients less than 12 years of age who are naïve to atypical antipsychotic medications and are experiencing no more than mild drowsiness (lightly sedated and can be aroused with speaking voice or light touch) can be observed at home unless they have ingested more than four times the initial adult dose for the implicated antipsychotic medication or a dose that is equal to or more than the lowest reported acute dose that resulted in at least moderate toxicity, whichever dose is smaller (i.e., aripiprazole 15 mg, clozapine 50 mg, olanzapine 10 mg, quetiapine 100 mg, risperidone 1 mg, ziprasidone 80 mg) (Grade D). 5) All patients 12 years of age or older who are naïve to atypical antipsychotic medications and are experiencing no more than mild drowsiness can be observed at home unless they have ingested more than five times the initial adult dose for the implicated antipsychotic medication (i.e., aripiprazole 50 mg, clozapine 62.5 mg, olanzapine 25 mg, quetiapine 125 mg, risperidone 5 mg, ziprasidone 100 mg) (Grade D). 6) Patients who use atypical antipsychotic medications on a chronic basis can be observed at home unless they have acutely ingested more than 5 times their current single dose (not daily dose) of the implicated antipsychotic medication (Grade C). 7) Patients who have ingested less than a threshold dose (see Recommendations 4-6) and are exhibiting no more than mild drowsiness can be observed at home with instructions to call the poison center if symptoms develop or worsen. If mild drowsiness is present at the time of the initial call, the poison center should make follow-up calls until at least 6 hours after ingestion. Consideration should be given to the time of day that home observation will take place. Observation during normal sleep hours might not be reliable. Depending on local poison center policy, patients could be referred to an emergency department if the observation would take place during normal sleeping hours of the patient or caretaker (Grade D). 8) Any patient already experiencing any signs or symptoms, other than mild drowsiness, thought to be related to atypical antipsychotic medication toxicity should be transported to an emergency department. Transportation via ambulance should be considered based on the condition of the patient and the length of time it will take the patient to arrive at the emergency department (Grade D). 9) Do not induce emesis (Grade D). 10) There are no specific data to suggest benefit from out-of-hospital administration of activated charcoal in patients exposed to atypical antipsychotic medications. Poison centers should follow local protocols and experience with the out-of-hospital use of activated charcoal in this context. Do not delay transportation in order to administer charcoal (Grade D). 11) For patients who merit evaluation in an emergency department, transportation via ambulance should be considered based on the condition of the patient and the length of time it will take the patient to arrive at the emergency department. Continuous cardiac monitoring should be implemented given reports of conduction disturbances associated with this class of medications. Provide usual supportive care en route to the hospital, including airway management and intravenous fluids for hypotension (Grade D). 12) Depending on the specific circumstances, follow-up calls should be made to determine outcome at appropriate intervals based on the clinical judgment of the poison center staff (Grade D).