When and why is intramuscular benzilpenicillin (penicillin+benzatin) advised for infectious cellulitis instead of oral antibiotics?

Antibiotic choices: There are actually a number of ways to treat infections. It's a complex topic that's worth discussing with your doctor. If you are not happy with them, you can ALWAYS find a second opinion. Treatment options these days are much better than in the past. I hardly ever use intramuscular penicillin -except for syphilis cases. It sounds like you need more information -so I would call your doc today.