I need to take bactrim (sulfamethoxazole and trimethoprim) for 10 days, but i just had cup of cherries. (not realizing they are high potassium) should i wait before taking bactrim (sulfamethoxazole and trimethoprim)?.

On Bactrim (sulfamethoxazole and trimethoprim): This should not be an issue with 1 cup of cherries (about 250 mg of potassium) assuming you have normal renal function and normal potassium levels to start with. And I assume these would be normal if your doctor placed you on Bactrim (sulfamethoxazole and trimethoprim).

Drink lots of water: Bactrim (sulfamethoxazole and trimethoprim) can cause problems with your kidneys in the right individual. Most fruit can contain high amounts of potassium. Just drink lots of water while taking Bactrim (sulfamethoxazole and trimethoprim) to prevent kidney stones.

Not necessarily: If you have kidney problems then you should probably avoid eating fruits high in potassium. Assuming that your kidneys are healthy then as long as you consume plently of water with your Bactrim (sulfamethoxazole and trimethoprim) you should be fine. Even so, call your prescribing physician. Especially if you were prescribed bactrim (sulfamethoxazole and trimethoprim) for a skin problem. I can't advise you of what to do safely as I do not know enough about you.