Final answer:
Tetracyclines are contraindicated for their potential to cause phototoxicity, discolored teeth, and liver toxicity, while chloramphenicol is limited by its serious toxic effects on bone marrow and risk of aplastic anemia.
Step-by-step explanation:
The tetracyclines and chloramphenicol are antibiotics with specific contraindications due to their side effects and mechanisms of action. Tetracyclines, which are broad-spectrum antibiotics that affect ribosome assembly, are contraindicated in cases of phototoxicity, the permanent discoloration of developing teeth, and potential liver toxicity, especially at high doses or in patients with kidney impairment. Chloramphenicol, known for its broad-spectrum coverage and ability to penetrate into tissues, is contraindicated due to its serious side effects including the potential for lethal gray baby syndrome, suppression of bone marrow production, aplastic anemia, and reversible, dose-dependent suppression of blood cell production. These side effects limit its use to severe infections that cannot be treated with less toxic alternatives.