I take 300mg twice a day of lithium & my bed time pill seems to knock me out (hard) & i find it hard to wake up 2. is that to much litium or toxicity?

Probably not.: Since you are taking lithium twice a day and didn't describe drowsiness after the morning dose, i doubt your sense of being "knocked out" at bedtime is coming from the lithium. 300 mg twice a day is a relatively low dose, so probably not too much or a toxic dose unless you have kidney failure. Toxicity usually causes a hand tremor, diarrhea, trouble walking, and lithium serum level would be high.

COULD BE: Your endocrinologist has to titrate the lithium so you have the right concentration for you without undesirable side effects.

BLOOD LEVEL/TALK MD: We can not answer if it is too much or just a side effect of lithium. You need to talk to your psychiatrist and also get a blood level done.