Apo-Fluoxetine Overdosage

During the clinical trials, there were two deaths among approximately 38 reports of acute overdose with fluoxetine, either alone or in combination with other drugs and/or alcohol. One death involved a combined overdose with approximately 1800 mg of fluoxetine and an undetermined amount of maprotiline were 4.57 mg/L and 4.18 mg/L, respectively.
A second death involved 3 drugs yielding plasma concentrations as follows: fluoxetine, 1.93 mg/L; norfluoxetine, 1.10 mg/L; codeine, 1.80 mg/L; temazepam 3.80 mg/L.
One other patient who reportedly took up to 3000 mg of fluoxetine experienced two grand mal seizures that remitted spontaneously without specific treatment. Since vomiting occurred, the amount of drug absorbed may have been less than that ingested.
In the postmarketing phase, there have been 16 confirmed reports of overdose of fluoxetine taken alone. The amount of drug ingested has varied from 80 mg to 2000 mg and the patients have ranged in age from 13 to 51 years. There have been no deaths in this group of patients, some of whom were treated vigorously absence of serious adverse events with the exception of a 13 year old male who ingested 1880 mg and experienced two brief seizures but thereafter had an uneventful recovery.
Since introduction, reports of death attributed to overdosage of fluoxetine alone have been rare.
Symptoms: Nausea and vomiting were prominent in overdoses involving higher fluoxetine doses. Other prominent symptoms of overdose included agitation, restlessness, hypomania and other signs of CNS excitation, including seizures.
Treatment: Establish and maintain an airway, incure adequate oxygenation and ventilation. Activated charcoal, which may be used with sorbitol, may be as or more effective than emesis or lavage, and should be considered in treating overdose.
Cardiac and vital signs monitoring is recommended, along with general symptomatic and supportive measures. Based on experience in animals, which may not be relevant to humans, fluoxetine-induced seizures which fail to remit spontaneously may respond to diazepam.
There are no specific antidotes for APO-FLUOXETINE (fluoxetine hydrochloride).
Due to large volume of distribution of APO-FLUOXETINE, forced diuresis, dialysis, hemoperfusion and exchange transfusion are unlikely to be of benefit.
In managing overdosage, consider the possibility of multiple drug involvement. The physician should consider contacting a poison control centre on the treatment of any overdosage.