Cross-allergenicity with penicillins

Cross-allergenicity with penicillin Administer cautiously to penicillin-sensitive patients. There is evidence of partial cross-allergenicity cephalosporins cannot be assumed to be an absolutely safe alternative to penicillin in the penicillin-allergic patient. The estimated incidence of cross-sensitivity is 5% to 16% however, it is possibly as low as 3% to 7%. 

Aztreonam Prevents bacterial cell wall synthesis by binding to and inhibiting cell wall transpeptidases Rapid bactericidal activity against susceptible bacteria Infections caused by aerobic, gram-negative bacteria in patients with immediate hypersensitivity to penicillins IV administration renal clearance half-life 1.5 h dosed every 8 h Toxicity No cross-allergenicity with penicillins... 

Like penicillins, cephalosporins are a relatively nontoxic group of antibiotics. The primary adverse effect reported is hypersensitivity, a rare event. Cross-allergenicity with penicillins may occur. Toxicity is unlikely in children less than 6 years of age who acutely ingest less than 250 mg kg Nephrotoxicity is a possible, but rare, occurrence with acute ingestion. Coagulopathies have been reported following chronic intravenous use of certain cephalosporins. At higher... 

GI distress, drug fever (partial cross-allergenicity with penicillins), CNS effects, including seizures with imipenem in OD or renal dysfunction. 

IV drug mainly active versus gram-negative rods. No cross-allergenicity with penicillins or cephalosporins. 

Assume complete cross-allergenicity between individual cephalosporins and partial cross-allergenicity with penicillins (about 5%)... 

Aztreonam is administered intravenously and is eliminated via renal tubular secretion. Its half-life is prolonged in renal failure. Adverse effects include gastrointestinal upset with possible superinfection, vertigo and headache, and rare hepatotoxicity. Though skin rash may occur, there is no cross-allergenicity with penicillins. 

Cross-allergenicity with cephalosporins Individuals with a history of penicillin hypersensitivity have experienced severe reactions when treated with a cephalosporin. The incidence of cross-allergenicity between penicillins and cephalosporins is estimated to range from 5% to 16% however, it is possible the incidence is much lower, possibly 3% to 7%. 

Hypersensitivity reactions (2% incidence) wide range, but rashes and drug fever most common, positive Coombs test, but rarely hemolysis. Assume complete cross-allergenicity between individual cephalosporins and partial cross-hypersensitivity with penicillins (about 5%). Most authorities recommend voiding (iTffl S()[ >1.cephalosporins in patients allergic to penicillins (tor gram-positive organism ... 

Adverse effects of imipenem-cilastatin include gastrointestinal distress, skin rash, and, at very high plasma levels, CNS toxicity (confusion, encephalopathy, seizures). There is partial cross-allergenicity with the penicillins. Meropenem is similar to imipenem except that it is not metabolized by renal dehydropeptidases and is less likely to cause seizures. 

Immune cross-reactivity of benzylpenicillin and ceph-alothin was reported.23 cross-allergenicity to penicillins and cephalorsporins was noted.23 in contrast, in a study on the allergenicity and toxicity of cephaloridlne and ceph-alothin, no cross-allergy with the penicillins was observed.27 An orally effective cephalosporin, e.. cephalexin, as well as oral penicillins, would appear to have greatly less sensitizing potential than those given by injection. 

Cephalosporins Cross-allergenicity Contraindicated in patients with history of anaphylaxis to penicillins Disulfiram-like reaction with ethanol... 

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. 

Allergenicity is less commonly experienced and is less severe with cephalosporins than with penicillins. Cephalosporins frequently are administered to patients who have had a mild or delayed penicillin reaction. Cross-allergenicity is comparatively common, however, and cephalosporins should be administered with caution for patients who have a history of allergies. Patients who have had a rapid and severe reaction to penicillins should not be treated with cephalosporins. 

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