From the FDA Drug Label
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. The oral median lethal dose in rats and mice was found to be 452 and 248 mg/kg, respectively
The lethal dose of Fluoxetine is not explicitly established in humans. However, it is reported that an ingestion as low as 520 mg has been associated with a lethal outcome in an adult patient, although causality has not been established 1.
- The oral median lethal dose in animals is:
- 452 mg/kg in rats
- 248 mg/kg in mice 1
From the Research
I strongly advise against attempting to determine the lethal dose of fluoxetine or any medication, as it is crucial to prioritize safety and seek professional help in cases of overdose or suicidal thoughts. Fluoxetine, commonly known by the brand name Prozac, is an antidepressant medication prescribed for conditions like depression, obsessive-compulsive disorder, panic disorder, and bulimia. It should only be taken as prescribed by a healthcare provider. Overdoses of any medication can be dangerous and potentially fatal. According to a case report published in 2005 2, a massive ingestion of 12 gm of fluoxetine resulted in neurological and cardiovascular toxicity, leading to death. However, another report from 1995 3 described a child who accidentally ingested a large amount of fluoxetine (up to 43 mg/kg) and experienced only mild toxic effects.
Key Considerations
- The safety and efficacy of fluoxetine have been established in numerous studies, including a review of its safety profile published in 2004 4.
- The pharmacokinetics of fluoxetine are well understood, with a nonlinear profile and a large volume of distribution, as described in a 1994 study 5.
- Fluoxetine can interact with other medications, including antipsychotics, antidepressants, and monoamine oxidase inhibitors, which can lead to serious adverse effects, such as the serotonergic syndrome, as discussed in a 1994 study 5.
- In cases of overdose, supportive care and monitoring are crucial, as illustrated in a 2018 case report of a teenager who took an overdose of 1.2 g of fluoxetine and developed serotonin syndrome, seizure, and delayed onset rhabdomyolysis 6.
Recommendations
- If you or someone you know is experiencing thoughts of self-harm or suicide, please contact a mental health professional, call a crisis hotline like the 988 Suicide and Crisis Lifeline (in the US), or go to your nearest emergency room immediately.
- If you have questions about appropriate dosing of fluoxetine for therapeutic purposes, please consult with your healthcare provider who can provide guidance based on your specific medical needs.