Can taking too much medicine kill you?

Levothyroxine drug is a narrow drug and that means it's dosage is very near the toxication dosage ...normally an adult would take between 100mcg and 125mcg it's unusal to to take 200mcg ..so i guess it needs 3 pills to die...this is scientific but in my experence i tried to suicide with levothyroxine 100 in my college in 2 hours i ate 30 pills and nothing happend excpect it makes you high and awkwardly happy my girlfriend left me if you asked why ...but that's not important :p