TOXICOLOGY■ Benzodiazepines for seizures
■ Sodium bicarbonate is notindicated for seizures (seizures are not due
to Na++channel blockade!).
■ Norepinephrine for hypotension unresponsive to fluid and sodium
bicarbonate
■ Magnesium sulfate if torsades de pointes
■ Avoid:
■ Physostigmine (no treatment benefit and may cause seizures)
■ Respiratory and/or metabolic acidosis (worsens Na++channel blockade)
■ Class IA and IC antidysrhythmics (fast Na++channel blockers)
■ Class III antidysrhythmics (K++channel blockers)
■ Phenytoin (no treatment benefit)
COMPLICATIONS
■ Aspiration
■ Hypoxic brain injury
■ Cardiovascular collapse
Selective Serotonin Reuptake Inhibitors
SSRIs are widely used for depression because of their large therapeutic win-
dow. Fatal overdoses are rare.
Examples include:
■ Fluoxetine (Prozac)
■ Citalopram (Celexa)
■ Paroxetine (Paxil)
MECHANISM/TOXICITY
■ Inhibition of presynaptic serotonin reuptake →increased CNS serotonin.
SYMPTOMS/EXAM
■ N/V, abdominal pain
■ Sinus tachycardia
■ CNS sedation and tremor
■ Less commonly—seizures, more serious cardiovascular toxicity
■ Serotonin syndromemay occur with overdose or routine use.
■ Autonomic dysfunction →hyperthermia (>38°C), diaphoresis.
■ CNS dysfunction →agitation and/or altered mental status.
■ Neuromuscular dysfunction →nystagmus, myoclonus, hyperreflexia,
muscular rigidity (lower extremities predominantly), tremor.
DIAGNOSIS
■ Clinical diagnosis is based on history of ingestion, constellation of signs,
and symptoms. Typical history includes increasing the dose of an SSRI or
more commonly, adding a second serotonergic agent.
■ SSRIs are not typically detected on standard toxicology screens.
TREATMENT
■ Supportive care
■ Activated charcoal if early and no CNS depression
Serotonin syndrome
may occur with overdose
or routine use.Serotonin syndrome is
characterized by increased
autonomic, CNS, and
neuromuscular activity.