Antibiotics desensitization

Penicillin desensitization is the most common drug desensitization protocol and is required for penicillin-allergic patients when penicillin is clearly the best treatment option, e.g., when syphilis is present in pregnancy. Protocols have been adapted to most antibiotics. Tables 51-5 and 51-6 describe procedures for oral and intravenous penicillin desensitization.25... 

Okamoto T, Sumikawa K. 1991. Antibiotics cause changes in the desensitization of ACh receptors expressed in Xenopus oocytes. Brain Res Mol Brain Res 9 (1-2) 165. 

Procedure Beta-lactam desensitization should be done in an intensive care unit and any concomitant risk factors for anaphylaxis, such as use of beta-blockers should be corrected. Protocols based on incremental use of the drug orally or parenterally have been described (190,193). The oral route is preferable and is associated with a lower incidence of adverse events, but mild transient reactions are frequent (171,194,195). Pregnant women with limited antibiotic choices have been treated with immunotherapy (196). Repeated administration will maintain a state of anergy, which is often lost after withdrawal (197). At the conclusion of therapy, patients must be informed that after withdrawal, they may once again become allergic to penicillin, with a new reaction to the first subsequent application (197). 

Sullivan TJ, Yecies LD, Shatz GS, Parker CW, Wedner HJ. Desensitization of patients allergic to penicillin using orally administered beta-lactam antibiotics. J Allergy Clin Immunol 1982 69(3) 275-82. 

In some patients the clinical presentation of red man syndrome is identical to that of acute IgE-mediated anaphylaxis. Vancomycin desensitization should therefore be considered for severe red man syndrome reactions that do not respond to premedication and a slower rate of infusion, and in anaphylactic reactions to vancomycin when substitution of another antibiotic is not feasible. Rapid desensitization is preferred, as it is effective in the majority of patients and enables administration of vancomycin within 24 hours. In patients who fail rapid desensitization, a slow desensitization protocol may be tried (90). 

Chopra N, Oppenheimer J, Derimanov GS, Fine PL. Vancomycin anaphylaxis and snccessfnl desensitization in a patient with end stage renal disease on hemodialysis by maintaining steady antibiotic levels. Ann Allergy Asthma Immunol 2000 84(6) 633-5. 

Answer B. Indications for the use of penicillin G are currently limited for a number of reasons. The drug has a narrow spectrum, is susceptible to beta-lactamases, and may cause hypersensitivity, and alternative antibiotics are available. However, penicillin G remains the drug of choice in syphilis, usually given IM as benzathine penicillin G, but as the Na or K salt IV in neurosyphilis. What would you do for patients who are highly allergic to penicillins (Consider tetracyclines, or possibly desensitization.)... 

Although there are risks associated with desensitization to a drug, a patient may, for example, show drug resistance to a possible alternative antibiotic and there may also be the possibility of faUure to control an infection by substituting a drug that provides poorer bioavaU-... 

---