Toxicology
Cyproheptadine is a histamine-1 receptor antagonist and nonspecific serotonin receptor antagonist.
A single dose of 8–12 mg by mouth should be administered for agitation and muscle rigidity as an
adjunct to benzodiazepines. A second dose may be administered in 6–8 hours if symptoms persist.
| d. | If condition worsens, may require intubation with continuous infusion benzodiazepines |
|---|
Although not well studied, case reports have shown the efficacy of dexmedetomidine at doses of
0.05–0.8 mcg/kg/hour (in pediatric patients).
Patient Case
A 21-year-old man is admitted to the ED after taking 30 citalopram 20-mg tablets about 2 hours ago. His
vital signs are as follows: BP 125/85 mm Hg, HR 77 beats/minute, RR 15 breaths/minute, and temperature
98.7°F (37.1°C). Which is the best intervention for this patient?
The atypical antipsychotic agents accounted for about 16,541 toxic exposures and 17 deaths in 2022.
antagonism. Additional effects include antagonism of the α1- and histamine-1 receptors.
Adverse effects associated with the atypical antipsychotics are typically self-limiting.
More severe adverse effects may include CNS depression, tachycardia, hypotension, and QT
prolongation.
Less severe adverse effects include dizziness, drowsiness, miosis, blurred vision, urinary retention,
and CNS excitation.
There are no specific antidotes for the atypical antipsychotics; general supportive care is recommended,
focusing on ABC.
administered within the first hour of exposure if no contraindications exist (J Emerg Med 2012;43:906-13).
Administer crystalloid to maintain BP with a goal mean arterial blood pressure >65 mm Hg, an SBP
greater than 90 mm Hg, and an HR greater than 60 beats/minute.
Consider vasopressors if fluid resuscitation is inadequate.
Because of the α-receptor antagonist activity of these agents, norepinephrine or phenylephrine is
preferred if vasopressors are needed.
Administer sodium bicarbonate if QRS prolongation is present (quetiapine overdose only)
Replace serum electrolytes, especially magnesium and potassium, if QT prolongation. Magnesium
replacement is recommended for membrane stabilization in patients with a QTc greater than 500
milliseconds and normal serum magnesium concentrations.