Cephalosporins allergy penicillins

The nurse should not administer cephalosporins if the patient has a history of allergies to cephalosporins or penicillins. 

Broad intravenous antibiotic coverage for the encapsulated organisms can include ceftriaxone or cefotaxime. For patients with true cephalosporin allergy, clindamycin may be used. If staphylococcal infection is suspected owing to previous history or the patient appears acutely ill, vancomycin should be initiated. Macrolide antibiotics, such as erythromycin and azithromycin, may be initiated if Mycoplasma pneumonia is suspected. While the patient is receiving broad-spectrum antibiotics, their regular use of penicillin for prophylaxis can be suspended. Fever should be controlled with acetaminophen or ibuprofen. Because of the risk of dehydration during infection with fever, increased fluid may be needed.6,27... 

Traditionally, high-dose penicillin G was the treatment standard for meningococcal disease. However, increasing penicillin resistance requires that third-generation cephalosporins now be used for empirical treatment until in vitro susceptibilities are known.23 Patients with a history of type I penicillin allergy or cephalosporin allergy may be treated with vancomycin. Treatment should be continued for 7 days, after which no further treatment is necessary. 

Because of cross-reactions between cephalosporins and penicillins, caution should be used when prescribing cephalosporins to patients with penicillin allergy. If a patient had anaphylaxis, angioedema, or urticaria fol-... 

For a patient with a history of penicillin/cephalosporin allergy, expert advice should be sought from a clinical microbiologist. Newer quinolone antibiotics such as levofloxacin and moxifloxacin are possible options but the BTS does not recommend monotherapy with these agents at present. 

Neither in vitro tests nor skin tests reliably predict cephalosporin allergy (166). The true frequency of allergic reactions in penicillin-allergic patients exposed to cephalosporins has been estimated to be 1 or 2% (167). Nevertheless, when there is a history of penicillin anaphylaxis or other severe IgE-mediated reactions, it is wise to avoid cephalosporins. 

Cross-reactivities between antibodies to cephalosporins and penicillins have been observed in experimental animals (Brandriss et al. 1965 Batchelor et al. 1966 Gralnick and McGinnis 1967 Tadokoro et al. 1976) and in man (Abraham et al. 1968 b Grieco 1967 Stemberger et al. 1971 Delafuente et al. 1979). Among 701 patients with a history of penicillin allergy, 57 (8.1%) experienced an... 

Park MA, Koch CA, Klemawesch P, Joshi A, Li JT. Increased adverse drug reactions to cephalosporins in penicillin allergy patients with positive penicillin skin test. Int Arch Allergy Immunol 2010 153 (3) 268-73. 

Fig. 5.3 Side-by-side two- and three-dimensional penicillin structure highlighting the side chain (R), p-lactam, and thiazolide ring structures. From Baldo BA. Diagnosis of allergy to penicillins and cephalosporins. Allergy Clin Immunol Int. 2000 12 206. Reprinted with permission from 2000 Hogrefe Huber Publishers (now Hogrefe Publishing, http //www.hogrefe.com)...

Some types of allergic reaction, for example immediate or delayed-type skin allergies, serum-sickness-like reactions and anaphylactic reactions, may occur in a proportion of patients given penicillin treatment. There is some, but not complete, cross-allergy with cephalosporins. 

As such, patients with penicillin allergies should be treated with a first-generation cephalosporin (if non-type I allergy), a macrolide/azalide, or clindamycin. Recurrent infections caused by reinfection, poor adherence to therapy, or true penicillin failure can be treated with amoxicillin-clavulanate, clindamycin, or penicillin G benzathine.45... 

Because GAS historically has been the primary causative organism, penicillin has been the mainstay of therapy. O However, the incidence ofS. aureus impetigo is increasing, so oral penicillinase-stable penicillins or first-generation cephalosporins are now preferred.3 Erythromycin is an alternative choice when penicillin allergy is a concern. Topical mupirocin may be used alone when there are few lesions.3... 

In uncomplicated cases, prompt oral antibiotic therapy with amoxicillin or a first-generation cephalosporin halts the progression of lymphangitis. Clindamycin may be used if the patient has a significant (1-lactam allergy. Intravenous antibiotics (penicillinase-stable penicillins, first-generation cephalosporins,... 

Verify the patient s allergy history and the type of reaction experienced. Attempt to discern between true allergy and adverse event. (3-Lactam-allergic patients may receive clindamycin, vancomycin, or other antimicrobials. Crossreactivity between penicillin allergy and cephalosporins is low but cephalosporins should be avoided in patients with a history of anaphylaxis to penicillins. 

If a patient has a mild, delayed allergy to penicillin, first-generation cephalosporins are effective alternatives but should be avoided in patients with an immediate-type hypersensitivity reaction. 

Serious infections should be treated intravenously with a penicillinase-resistant penicillin (nafcillin) or first-generation cephalosporin (cefazolin). Patients with penicillin allergies should be treated with vancomycin or clindamycin. 

Penicillins and cephalosporins bind irreversibly to serum albumin. It has been shown that drug-protein conjugates result from the aminolysis of the /3-lactam bond by the e-amino group of lysine residues in the protein (Fig. 5.1, Pathway e). The bound penicilloyl group appears to be the major antigenic determinant of penicillin allergy [145-148],... 

Cephalosporins are sensitizing and may elicit a variety of hypersensitivity reactions that are identical to those of penicillins, including anaphylaxis, fever, skin rashes, nephritis, granulocytopenia, and hemolytic anemia. However, the chemical nucleus of cephalosporins is sufficiently different from that of penicillins so that some individuals with a history of penicillin allergy may tolerate cephalosporins. The frequency of cross-allergenicity between the two groups of drugs is uncertain but is probably around 5-10%. However, patients with a history of anaphylaxis to penicillins should not receive cephalosporins. 

It has also been reported that patients with allergic-like events after penicillin treatment have had a markedly risk of events after subsequent cephalosporin antibiotics. Cross-reactivity is not an adequate explanation for this increased risk and the data obtained indicate that cephalosporins can be considered for patients with penicillin allergy <2006MI354.ell>. Comparisons of parenteral broad-spectrum cephalosporins have been tested against bacteria isolated from pediatric patients. The results have indicated that cefepime has been the most broad-spectrum cephalosporin analyzed and it is a very potent alternative for the treatment of contemporary pediatric infections in North America <2007MI109>. The historical safety of the most commonly used oral cephalosporins has been reviewed <2007MIS67>. The antimicrobial spectrum and in vitro potency of the most frequently prescribed orally administered cephalosporins (cefaclor, cefdinir, cefpodoxime, cefprozil, cefuroxime axetil and cephalexin has also been reviewed <2007MIS5>. 

Allergic manifestations The cephalosporins should be avoided or used with caution in individuals allergic to penicillins (about 5 to 15% show cross-sensitivity). In contrast, the incidence of allergic reactions to cephalosporins is 1-2% in patients without a history of allergy to penicillins. 

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