Autonomic instability in a dehydrated child on guanfacine: Case report and literature review

A case of pulmonary edema due to guanfacine intoxication with measurement of serum guanfacine concentrations

Guanfacine hydrochloride extended-release (GXR) is used to treat attention deficit hyperactivity disorder. It is a selective α2A-adrenorecepor agonist that was reported to cause QT prolongation and hypotension in the event of overdosing. We report the case of a 17-year-old man who took 226 tablets of GXR 3 mg for attempted suicide. He was found complaining of dyspnea, and emergency medical services were called. When the patient was transferred to our hospital, his Glasgow coma scale was 12 (E4V3M5). He was agitated and hypoxemic. He was intubated for invasive mechanical ventilation under sedation. His chest X-ray and computed tomography scan showed pulmonary edema. Transthoracic echocardiography showed markedly reduced cardiac function. His serum guanfacine concentration peaked on day 3 after admission. His pulmonary edema improved quickly after a decrease in serum guanfacine concentration, but cardiac decompensation persisted for about 1 month. This case reveals that the decline in cardiac function after guanfacine intoxication is prolonged even after its serum concentration has decreased.

Exposures to psycholeptics, psychoanaleptics, and cardiovascular drugs reported to the PIC erfurt during heat waves from 2003 to 2018

Psycholeptics, psychoanaleptics, and cardiovascular drugs alter individual tolerance to extreme heat. To explore the influence of heat waves on their toxicity in acute overdose, we retrospectively analyzed all human exposures to psycholeptics and psychoanaleptics (PLAexp) as well as cardiovascular drugs (CVDexp) registered by the Poisons Information Center (PIC) Erfurt between June to September of the years 2003 to 2018 for frequency, age groups, sex, circumstances of exposure, and symptom severity. The results of the non-heat years (NHY) 2004-2005 and 2007-2014 (average air temperature June-September 16.2 °C) were compared to the results of the heat years (HY) 2003, 2006 and 2015-2018 (average air temperature June-September 17.5 °C). In total, 13,191 cases (HY 5,117; NHY 8,074) of PLAexp and 2,960 cases (HY 1,168; NHY 1,792) of CVDexp were registered. During HY, accidental PLAexp (11.2% versus 9.7%) and CVDexp (40.6% versus 36.8%) were more often seen. Severe symptoms were less frequent in PLAexp (4.4% versus 6.3%) and CVDexp (3.3% versus 4.9%). Although in HY, no higher rates of moderate or severe PLAexp and CVDexp were detected than in NHY, patients with these medications should be observed carefully during heat waves because of affected body's usual cooling mechanisms.

Guanfacine toxic ingestion with subsequent cardiogenic pulmonary edema

Guanfacine is a central alpha-2 agonist often prescribed for Attention-deficit hyperactive disorder as well as tic disorder, with a usual dose of 1-4 mg per day. Due to its sympatholytic mechanism of action, Guanfacine can cause autonomic instability and hypotension. It can additionally cause cardiac dysfunction to include symptomatic bradycardias and contractility suppression. The authors present a case of a 17 year-old male with an ingestion of 80 mg of extended release Guanfacine with delayed onset cardiogenic pulmonary edema requiring mechanical ventilation. Previous pediatric ingestions have generated bradycardia, hypotension, and decreased level of consciousness, responsive to intravenous fluids, vasopressors, and occasionally naloxone. However, cardiogenic pulmonary edema from reduced cardiac contractility is a novel consequence of extended release Guanfacine ingestion. With Guanfacine's extended half-life, this unique case underscores the importance of emergency providers' familiarity with this toxidrome as well the necessity for prolonged, close observation following Guanfacine ingestion.