The use of antimicrobial agents for noninfectious diseases.

Antimicrobial agents are used in the treatment of a variety of noninfectious diseases. Therapeutic action may be directed against the host immune system as well as against the microbe. Some actions conventionally classified as toxic may be therapeutically or diagnostically desirable under unusual clinical circumstances. Antibiotics are used for both their antimicrobial and antiinflammatory properties to treat several dermatologic and immune-mediated diseases. Tetracycline fluorescence indicates necrotic or malignant tissue and the depth of dermal burns. Tetracycline's affinity for new bone tissue formation has applications in both research and diagnostic assessments. Radiolabeled tetracycline can act as an imaging agent for the gall bladder and kidney. The sulfonamides and sulfones, chloramphenicol, metronidazole, and some aminoglycosides also have been demonstrated to have unusual therapeutic and diagnostic efficacy, albeit by mechanisms not always understood. Although not all reported unconventional applications of antimicrobial agents remain in use, sharpening awareness of their multifaceted actions should encourage broader understanding of all agents traditionally confined to specific uses.