Hi: My Partner Is Taking Medication For Water Retention. (the

Hi:
My partner is taking medication for water retention. (the doctor double the dose (2 tablets / day). His stomach is upset, he cannot get a good nights sleep even though he takes strong sleeping pills, he is also a type 2 diabetic. Is sleep deprivation a side effect of "latex pill" as well as an upset stomach? Due to the fluid around the intestines he is never hungry and can go days without eating. He has just started to drink "ensure" as he has no energy or strength. Also his skin has been very itchy since taking the "latex pill". Please advise symptons and complications and if you require anymore information. He has been to his cardiologist recently.
HELP, please.