Table 2.

Toxica and immunotoxic adverse events mediated by antibacterial agents

Side effect (frequency)Mechanism
Neutropenia and agranulocytosis
 Chloramphenicol (1/20,000; 50% mortality)Toxicity (nitrosoderivative, dehydrochloramphenicol)
 β-Lactams (5–15%)Toxicity
 Semisynthetic penicillins, high dose, long term Methicillin (8%) Cephalosporins (0.1%)(in vitro: cephalosporins, imipenem > penicillins > monobactams; in vivo: penicillins > cephalosporins) Antibodies Individual susceptibility
 Sulfonamides (0.1%)Toxicity plus antibodies (phagocyte-mediated drug alteration) plus genetic defect (detoxifying enzymes)
 Co-trimoxazole (10%)
 Dapsone (0.01%)
 Maloprim (pyrimethamine + dapsone) (0.5%)
 Isoniazid, clindamycin, PAS, rifampin, ethambutol, aminoglycosides, ciprofloxacin (in vitro + TNF) (0.1 to 0.5%)Toxicity for progenitor cells
Autoimmune diseases
 Systemic lupus erythematosus antinuclear antibodies: isoniazid (20%)Immune complexes (PMN-mediated oxidation of isoniazid)
 Lupus syndromes: sulfonamides, nitrofurantoin
 Autoimmune anemia, thrombocytopenia; penicillins, cyclines, cephalosporins, streptomycin, sulfonamides, nitrofurantoin, etc.Antibodies
Hypersensitivity
 Anaphylaxis: penicillin G (2%)Allergy, pseudoallergy
 Immediate hypersensitivity: penicillin G (0.7–10%), clindamycin (10%), co-trimoxazole (6%), gentamicin, streptomycin, isoniazid (2%), amikacin, chloramphenicol, p-aminosalicylic acid, rifampin, trimethoprim (0.5–2%), erythromycin, tetracycline, vancomycin (0.1–0.5%) (streptomycin: peripheral PMN)Drug metabolism by phagocytes
  • a Note that only adverse effects related to the immune system are presented here.