Can Keflex be bad for a diabetic?

Actually the infection is a heck of a lot worse for diabetes then the keflex. Docs need to know that you're diabetic when they prescribe the keflex to know that it will probably be harder to get rid of the infection.

Before using Keflex, tell your doctor if you are allergic to any drugs (especially penicillins), or if you have:

kidney disease;
liver disease;
a stomach or intestinal disorder such as colitis;
diabetes; or
if you are malnourished.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take Keflex.

The oral suspension (liquid) form of Keflex may contain sugar. This may affect you if you have diabetes.

Read more at: https://www.drugs.com/keflex.html

Take care,

maso.-