Expansion
Each class has a signature adverse effect
Expansion
| Class | Signature toxicity |
|---|---|
| Penicillins | Hypersensitivity, rash; amoxicillin rash in glandular fever |
| Cephalosporins | C difficile, cross-reactivity with penicillin allergy |
| Aminoglycosides | Nephrotoxicity, ototoxicity (irreversible), neuromuscular blockade |
| Macrolides | QT prolongation, nausea, enzyme inhibition |
| Tetracyclines | Photosensitivity, tooth discolouration, avoid under 12 and in pregnancy |
| Quinolones | Tendon rupture, QT prolongation, seizures, C difficile, aortic aneurysm |
| Clindamycin | C difficile colitis, the classic association |
| Trimethoprim | Hyperkalaemia, raised creatinine, folate antagonism, teratogenic |
| Metronidazole | Disulfiram reaction with alcohol, peripheral neuropathy, metallic taste |
| Vancomycin | Red man syndrome (infusion rate related, not allergy), nephrotoxicity |
| Chloramphenicol | Aplastic anaemia, grey baby syndrome |
| Rifampicin | Orange secretions, hepatitis, potent enzyme inducer |
| Nitrofurantoin | Pulmonary fibrosis, neuropathy, avoid at term and in renal impairment |
The four C antibiotics most associated with C difficile are worth grouping: clindamycin, cephalosporins, co-amoxiclav and ciprofloxacin.