Adverse drug reactions from antibiotics

Counsel the patient regarding adherence to prophylactic antibiotic, antifungal, and antiviral regimens. Evaluate the patient for infection and adverse drug reactions to antibiotics, antifungals, and antivirals. Ensure that the patient is appropriately immunized after recovery from HCT. 

As with all drugs, the specific side effects of the quinolones must be considered when they are chosen for treatment of bacterial infections [5]. Reactions of the gastrointestinal tract and the central neivous system are the most often observed adverse effects during therapy with quinolones. It should be underlined, however, that compared with many other antimicrobials, diarrhea is less frequently observed during quinolone treatment. Antibiotic-associated colitis has been observed rarely during quinolone therapy. Similarly, hypersensitivity reactions, as observed during therapy with penicillins and other (3-lactams, is less frequently caused by quinolones. Some other risks of quinolone therapy have been defined and must be considered if a drug from this class is chosen for treatment of bacterial infections. 

The penicillins [pen i SILL in] are the most widely effective antibiotics and are among the least toxic drugs known the major adverse reaction to penicillins is hypersensitivity. The members of this family differ from one another in the R substituent attached to the 6-aminopenicillanic acid residue. The nature of this side chain affects their antimicrobial spectrum, stability to stomach acid, and susceptibility to bacterial degradative enzymes (P-lactamases). Figure 30.1 shows the main structural features of the penicillins. Figure 30.2 shows the classification of agents affecting cell wall synthesis. 

Upon systemic distribution, many drugs evoke skin reactions that are caused on an immunological basis. Moreover, cutaneous injury can also arise from nonimmunological mechanisms. Cutaneous side effects vary in severity from harmless to lethal. Cutaneous reactions are a common form of drug adverse reaction. Nearly half of them are attributed to antibiotics or sulfonamides, and one-third to nonsteroidal anti-inflammatory agents, with many other pharmaceuticals joining the list... 

The most prominent adverse reaction of the lincosamides is diarrhea, which varies from mildly loose bowel movements to life-threatening pseudomembranous colitis (see monograph on Beta-lactam antibiotics). Almost all antimicrobial drugs have been associated with severe diarrhea and colitis however, lincomycin and clindamycin have been particularly incriminated. The incidence of clindamycin-induced diarrhea in hospital is 23%. Diarrhea resolves promptly after withdrawal in most cases. It seems to be dose-related and may result from a direct action on the intestinal mucosa. Severe colitis due to C. difficile is not dose-related and occurs in 0.01-10% of recipients. Clustering of cases in time and place suggests the possibility of cross-infection. Even low doses of clindamycin, in some cases after topical administration, can cause marked alterations in several intestinal functions related to bowel flora (23). There was reduced susceptibility of C. difficile to clindamycin in 80% of French isolates in 1997 (24). Lincomycin was among the antibiotics that were most often associated with the development of antibiotic-associated diarrhea in a Turkish study of 154 patients other associated antibiotics were azithromycin and ampicillin (25). 

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