| penicillin → IsA → antibiotic | 0.62 | |
| penicillin → IsA → beta-lactam antibiotics | 0.52 | |
| penicillin → IsA → the drug of choice | 0.46 | |
| penicillin → IsA → the oldest class of antibiotics | 0.30 | |
| penicillin → IsA → a wonder drug | 0.16 | |
| penicillin → IsA → the most common drug allergy | 0.16 |