Antibiotics such as chloramphenicol can interfere with the blood-forming cells in the bone marrow, possibly resulting in reversible or irreversible (fatal) anemia. Some drugs hemolyze red blood cells, others can cause leukopenia, and still others can damage platelets, thereby interfering with blood clotting.

Certain antimicrobial drugs can affect the brain and cause seizures; others, such as aminoglycosides, can damage nerves (commonly the eighth cranial nerve) and cause dizziness, vertigo, and deafness. When drugs block the transmission of impulses to the diaphragm, respiratory failure can be the result.

The skin is a frequent target of antibiotic adverse effects. Skin disorders can be a symptom of an allergic reaction or a sign of direct toxic effects. Some antibiotics (tetracyclines) may interact with sunlight and cause photodermatitis.

Tetracyclines are contraindicated for children under the age of 8 years because they bind to enamel of the teeth and cause discoloration. Pregnant women should avoid tetraclyclines because they can cross the placenta and affect the development of bones and teeth in the fetus.

Copyright © 2001 by Quintessence Publishing Co, Inc (www.quintpub.com), 551 Kimberley Drive, Carol Stream, IL 60188. Reproduced with permission.