since diuretics ("water pills") can lead to elevated blood glucose and lipids, you'd probably be wise to control eating habits while on them. You'd also likely want to make sure that you replace potassium and magnesium.
Depends on whether the swelling is from fluid retention or something else. Where would you get "fluid" tablets? Has the doctor already prescribed them for you? There are probably directions how to use them then. If this is something new, you should check in with your doctor.