Does pain killers absorb faster post sleeve?

Odd quesiton, bare with me how I word it.

Does tablets like pain killers absorb faster, and have more side effects due to the less amount of stomach?

I am asking as I am in hospital and on morphine and they give me morphine 10mg another pain killer and something else at the same time.

I feel more sleepy and blury alot sooner, its not the weightloss as i have had morphine this weight before. So I wonder if its being absorbed faster? ( I have no food in my system as I am nill by mouth ) so the empty stomach probably doesnt help, they prescribed me fortisip which i have refused to have as im over weight lol and don t need it ) but i wonder if i had a sip of that before having the morphine it may help so just curious.

If people say it does absorb faster hense harsher side effects i can space it out and have half a dose