there is no such thing as fasting while taking a drug at the same time. also this drug you mention has awful side effects which completely makes the fast 1000X harder than it has to be
the whole point of fasting is NOT to put anything in your body except water (in a water fast). or nothing at all (in a dry fast)
also unless you are super skinny and famined there is no such thing as hunger. how many times does a fat person say "i'm hungry, lets go to chikfilA". it isn't hunger, it is an addiction to junk food. these places are clever, they add in ingredients that make the food addictive to people.
when you feel hungry it is actually either a compulsion or it is your body saying 'don't feed me'. we grew up with our parents shoving food down our throats all the time so we developed these bad habits.
the bottom line is fasting is much easier than people think. you just don't eat food lol. just do it. if you get an urge to walk to the fridge just meditate or go for a short walk around the block and that fake hunger pain will be gone. by day 3 you won't feel hungry at all.