 [ Symptoms ] i lost my cephalexin prescription can i use my tetracycline in place of the cephalexin [ Disease ] i have no idea what medicine your doctor used podophylin cantharidin you are going to need to call your doctor about this one since i do not know the details of your case the extent of the treatment what was used or what your instructions were some of those medications must be washed off in 4 6 hours but again i do not know what was used