Fluoxetine overdose
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overdose Information
General
Adult Overdose
Pediatric Patients (ages 3 months to 17 years)
Other important adverse events
Management of Overdose
General
Worldwide exposure to fluoxetine hydrochloride is estimated to be over 38 million patients (circa 1999). Of the 1578 cases of overdose involving
fluoxetine hydrochloride, alone or with other drugs, reported from this population, there were 195 deaths. Return to top
Adult Overdose
Among 633 adult patients who overdosed on fluoxetine hydrochloride alone, 34 resulted in a fatal outcome, 378 completely recovered, and
15 patients experienced sequelae after overdosage, including abnormal accommodation, abnormal gait, confusion, unresponsiveness, nervousness,
pulmonary dysfunction, vertigo, tremor, elevated blood pressure, impotence, movement disorder, and hypomania. The remaining 206 patients had an
unknown outcome. The most common signs and symptoms associated with non-fatal overdosage were seizures, somnolence, nausea, tachycardia,
and vomiting. The largest known ingestion of fluoxetine hydrochloride in adult patients was 8 grams in a patient who took fluoxetine alone and who
subsequently recovered. However, in an adult patient who took fluoxetine alone, an ingestion as low as 520 mg has been associated with lethal
outcome, but causality has not been established. Return to top
Pediatric Patients (ages 3 months to 17 years)
Among pediatric patients (ages 3 months to 17 years), there were 156 cases of overdose involving fluoxetine alone or in combination with other
drugs. Six patients died, 127 patients completely recovered, 1 patient experienced renal failure, and 22 patients had an unknown outcome. One of the
six fatalities was a 9-year-old boy who had a history of OCD, Tourette’s syndrome with tics, attention deficit disorder, and fetal alcohol syndrome. He
had been receiving 100 mg of fluoxetine daily for 6 months in addition to clonidine, methylphenidate, and promethazine. Mixed-drug ingestion or other
methods of suicide complicated all 6 overdoses in children that resulted in fatalities. The largest ingestion in pediatric patients was 3 grams which was
nonlethal. Return to top
Other important adverse events
Other important adverse events reported with fluoxetine overdose (single or multiple drugs) include coma, delirium, ECG abnormalities (such as
QT interval prolongation and ventricular tachycardia, including torsades de pointes-type arrhythmias), hypotension, mania, neuroleptic malignant
syndrome-like events, pyrexia, stupor, and syncope. Return to top
Management of Overdose
Treatment should consist of those general measures employed in the management of overdosage with any drug effective in the treatment of major
depressive disorder.
Ensure an adequate airway, oxygenation, and ventilation. Monitor cardiac rhythm and vital signs. General supportive and symptomatic measures
are also recommended. Induction of emesis is not recommended. Gastric lavage with a large-bore orogastric tube with appropriate airway protection,
if needed, may be indicated if performed soon after ingestion, or in symptomatic patients.
Activated charcoal should be administered. Due to the large volume of distribution of this drug, forced diuresis, dialysis, hemoperfusion, and
exchange transfusion are unlikely to be of benefit. No specific antidotes for fluoxetine are known.
A specific caution involves patients who are taking or have recently taken fluoxetine and might ingest excessive quantities of a TCA. In such a case,
accumulation of the parent tricyclic and/or an active metabolite may increase the possibility of clinically significant sequelae and extend the time
needed for close medical observation.
Based on experience in animals, which may not be relevant to humans, fluoxetine-induced seizures that fail to remit spontaneously may respond to
diazepam.
In managing overdosage, consider the possibility of multiple drug involvement. The physician should consider contacting a poison control center for
additional information on the treatment of any overdose. Telephone numbers for certified poison control centers are listed in the Physicians’ Desk. Return to top
Adapted from the FDA Package Insert.