tailieunhanh - Chapter 127. Treatment and Prophylaxis of Bacterial Infections

The development of vaccines and drugs that prevent and cure bacterial infections was one of the twentieth century's major contributions to human longevity and quality of life. Antibacterial agents are among the most commonly prescribed drugs of any kind worldwide. Used appropriately, these drugs are lifesaving. However, their indiscriminate use drives up the cost of health care, leads to a plethora of side effects and drug interactions, and fosters the emergence of bacterial resistance, rendering previously valuable drugs useless. . | Chapter 127. Treatment and Prophylaxis of Bacterial Infections The development of vaccines and drugs that prevent and cure bacterial infections was one of the twentieth century s major contributions to human longevity and quality of life. Antibacterial agents are among the most commonly prescribed drugs of any kind worldwide. Used appropriately these drugs are lifesaving. However their indiscriminate use drives up the cost of health care leads to a plethora of side effects and drug interactions and fosters the emergence of bacterial resistance rendering previously valuable drugs useless. The rational use of antibacterial agents depends on an understanding of 1 the drugs mechanisms of action spectrum of activity pharmacokinetics pharmacodynamics toxicities and interactions 2 mechanisms underlying bacterial resistance and 3 strategies that can be used by clinicians to limit resistance. In addition patient-associated parameters such as infection site other drugs being taken allergies and immune and excretory status are critically important to appropriate therapeutic decisions. This chapter provides specific data required for making an informed choice of antibacterial agent. Mechanisms of Action Antibacterial agents like all antimicrobial drugs are directed against unique targets not present in mammalian cells. The goal is to limit toxicity to the host and maximize chemotherapeutic activity affecting invading microbes only. Bactericidal drugs kill the bacteria that are within their spectrum of activity bacteriostatic drugs only inhibit bacterial growth. While bacteriostatic activity is adequate for the treatment of most infections bactericidal activity may be necessary for cure in patients with altered immune systems . neutropenia protected infectious foci . endocarditis or meningitis or specific infections . complicated Staphylococcus aureus bacteremia . The mechanisms of action of the antibacterial agents to be discussed in this section are summarized in .