What is considered a fatal dose of lithium?

Lithium toxicity: Can occur at doses very close to therapeutic dosing. 0.5mEq/kg/d usually puts a person at about 1.5 mEq/L serum levels. For a 70 kg person with normal kidney function, that translates to about 1200 mg of lithium per day(4 300mg pills/day). Above that and monitoring has to be very tight to prevent adverse reactions.

Varies: serious and harmful drug overdoses vary especially with drugs like lithium. it depends on several factors . best to avoid overdose is to work closely with your prescribing physician

Blood serum level: Serious, often fatal consequences occur when the blood serum concentrations are found to be of more than 2 mq per liter. More important than the dose taken is the individual's accumulation and only medical measures can determine this. It is a very poor choice for anyone to make when feeling overwhelmed by life. If this is you. Call 1-800-273-8255 for confidential help.