bacterial infection
"I'm allergic to penicillin and clindamycin has been a blessing over the years for serious infections after other non-penicillin antibiotics have failed.  In 2007 for a severe dental infection, and now for a strep infection in my leg.  The doctors do not want to use this 'first' because it is so strong.  Little bit of funky taste, drowsiness but overall  I tolerate it OK."