Is it OK to take leftover antibiotics to treat a current infection?
You should never use any leftover antibiotics to treat a current infection. The various
antibiotics that are available are effective only against specific bacteria, so do not assume
that the old medication will take care of your current infection. Your physician should
determine the cause of your infection and prescribe appropriate treatment.
It also is important to note that any time you are prescribed an antibiotic, you should take all the medicine you are given on the schedule your doctor provides - even when you start to feel better. Unless your doctor tells you to discontinue the antibiotic, you should not have any left over. Not finishing the prescription means some bacteria could survive and possibly come back even stronger. The surviving bacteria can then become resistant to the antibiotic, make the infection worse and make it harder to treat.
Learn more about your medication.