I've been on Dapagliflozin (Forxiga/Farxiga) since December. No day-to-day side effects generally speaking, though I would strongly advise caution and careful monitoring if you are on a very low-carb diet, if you drink alcohol in considerable quantities, or (worst case) both. The most serious risk perhaps is Euglycemic Diabetic Ketoacidosis -
Link to further information
I have had two experiences which I believe might have been the early stages of this issue, once on New Years Day and again last week. Both times I drank too much alcohol until very late the night before, both times I didn't have to get up in the morning so I slept in very very late, both times I woke up feeling sweaty, shaky and generally felt 'weird'. I happen to have a ketone monitor and both times I tested my ketones. Both times my ketone levels were elevated - 2 point something on New Years Day and 1.9 mmol/L last week. I am not on a particularly low-carb diet and certainly the second time my ketone level should have been zero before I went to bed. Both times I had eaten before going to bed (a dinner earlier, then snacking on lots of nuts) but because I decided to sleep off my hangover I did not eat again until late the next day.
I caught the event last week on a CGM - during the night my blood glucose slowly went down in the hours after I went to sleep, dipped into the red maybe 4 or 5 hours later, and stayed low, in a long very flat red line. I did not feel dizzy or confused, but seeing this on the CGM when I woke up I tested my BG (several times) with my finger-prick meter. The reading was 2.8 mmol/L. I speculate that the excessive alcohol, plus the period of 'fasting' when I stayed in bed all day and didn't eat, perhaps combined with the effect of the medication, put me in a long state of hypoglycaemia. I don't know if this happened on New Years Day or not as that time around I ate before I thought to test my blood. Could this happen without those meds in my system? I don't know - I would have thought if it was due to alcohol only my BG should started to rise again at some point. On both occasions the 'I felt weird' feeling was unlike a typical hangover feeling for me, which is why I decided to test my ketones the first time around. Something was 'off'.
Both times I ate plenty, drank lots of water, and felt fine not too long afterwards. It's perhaps possible that had I not eaten a substantial amount of carbs though my BG level might have stayed very low and my ketone levels might have continued to climb rapidly.
Bear in mind that I have drank alcohol many times while on this medication. For a while after the first incident I took to skipping my second pill of the day if I intended to drink substantially that night. I stopped doing that after a while but did not experience any issues until last week. I was on holiday a few weeks ago, for two weeks, and did quite a bit of drinking without any changes to the meds and felt fine. What both events had in common was a particularly large amount of alcohol drank and not having to get up for anything the next morning, thus letting me sleep in very late without eating anything.
If you're not a big drinker or on a very low carb diet I wouldn't be particularly worried. The risk factors are listed on the website I linked. If you feel that this might be a concern for you it's probably worth keeping a close eye on.
