Penicillin is excreted in urine by renal clearance. Penicillin is an antibiotic indicated in the treatment of infections due to penicillin G-sensitive microorganisms. Examples of those infections are streptococcal infections, pneumococcal infections, staphylococcal infections, and Vincent’s gingivitis and pharyngitis. Penicillin works by inhibiting the synthesis of bacterial cell wall. Reference 1) Penicillin. DailyMed URL: . Accessed December 29, 2017.