Antibiotics and infectious diseases.

Selection of antibiotics in clinical practice has become increasingly complex because more patients have underlying predispositions to infection, a greater variety of microorganisms with varying antibiotic resistance patterns cause these infections, and more antibiotics are available to treat these pathogens. A practical approach to antibiotic decision-making involves comparing the advantages and disadvantages of each group of antibiotics available while remembering the patient population being treated and the common pathogens encountered in one's practice. It is helpful to study the penicillin derivatives in approximately chronologic order of development and the cephalosporins in terms of generations because this puts the use of each individual agent in perspective. Familiarity with commonly encountered adverse antibiotic reactions, dosage guidelines, and special situations (pregnancy, pediatric patients) will help avoid problems associated with antibiotic use. Finally, having one or more useful references at hand will aid in resolving questions about antibiotic use.