| Term | Definition |
| ß-Lactam Antibiotics | Natural Penicillins , Antistaphylococcal , Extended Spectrum , Anti Pseudomonal |
| Natural Penicillins | Penicillin G , Penicillin V |
| Antistaphylococcal | Methithilin, Nafcilin , Oxacillin , Cloxacillin , Dicloxacillin. |
| Extended Spectrum | Ampicillin , Amoxicillin. |
| Antipseudomonal | Ticarcillin , Piperacillin , Carbencillin , Mezlocillin |
| Penicillin G | Active against gram +ve , gram -ve Cocci , gram +ve Bacilli and Spirochetes ( Liptospira , Boriella Begdofferi ) |
| Penicillin V | more acid-stable than Penicillin G , oral infections , effective against anaerobic organisms. |