No experience with Letrozole tablets overdose has been reported. In single dose studies the highest dose used was 30 mg, which was well tolerated; in multiple dose trials, the largest dose of 10 mg was well tolerated.
Lethality was observed in mice and rats following single oral doses that were equal to or greater than 2000 mg/kg (about 4000 to 8000 times the daily maximum recommended human dose on a mg/m2 basis); death was associated with reduced motor activity, ataxia and dyspnea. Lethality was observed in cats following single IV doses that were equal to or greater than 10 mg/kg (about 50 times the daily maximum recommended human dose on a mg/m2 basis); death was preceded by depressed blood pressure and arrhythmias. There is no experience in humans with an overdose of Letrozole tablets, so firm recommendations for treatment are not possible. Emesis could be induced if the patient is alert. In general, supportive care and frequent monitoring of vital signs is appropriate.