| Class | Examples | Mechanisms |
| ß-Lactams | Penicillin, ampicillin, cephamycin, carbapenem | ß-Lactamases, altered penicillin-binding proteins (PBP); efflux |
| Aminoglycosides | Gentamicin, kanamycin, amikacin, tobramycin | Modification of antibiotic by acylation, phosphorylation, or adenylylation |
| Tetracyclines | Tetracycline, minocycline | Efflux; ribosomal protection |
| Chloramphenicol | Chloramphenicol | Modification of acylation |
| Fluoroquinolones | Ciprofloxacin, enrofloxacin, sparfloxacin | Mutational alteration of target (GyrA, Topo IV, Par); efflux |
| Macrolides | Erythromycin, clarithromycin | Modification of 23S RNA by methylation |
| Glycopeptides | Vancomycin, teicoplanin | Alteration of antibiotic binding site in cell envelope |
| Macrolides | Erythromycin, clarithromycin | Modification, amplification, or substitution of target dihydropteroate synthase |
| Trimethoprim | Trimethoprim | Amplification or substitution of target dihydrofolate reductase |
| Ansamycin | Rifamycin | Mutational alteration of RNA polymerase ß-subunit; occasionally ribosylation of drug |
| Isoniazid | Isoniazid | Prevention of inactivation of pro-drug (kat) or modification of target pathway (inhA kasA) |
| Azoles | Ketoconazole, fluconazole | Efflux; mutational alteration of lanosterol demethylase |