Hypersensitivity reactions clinical assessment

Clavulanic acid has a very low immunogenic and allergenic potential in animals. The possible impact of its co-administration with other beta-lactam antibiotics is unknown (53). Two patients with IgE-mediated hypersensitivity to oral co-amoxiclav and positive skin tests for clavulanic acid, but not for penicillins, both tolerated oral amoxicillin. One patient was also challenged with clavulanic acid and developed urticaria, conjunctivitis, and bronchial obstruction (54). Since co-amoxiclav has been widely used since its introduction in 1981, the frequency of hypersensitivity reactions is low. The clinical data available on sulbactam and tazobactam are stiU hm-ited and do not allow an assessment of the frequency and pattern of associated hypersensitivity reactions (55). 

Pirmohamed M, Graham A, Roberts P, Smith D, Chadwick D, Breckenridge AM, Park BK (1991) Carbamazepine hypersensitivity assessment of clinical and in vitro chemical cross-reactivity with phenytoin and oxcarbazepine. Br J Clin Pharmacol 32 741-749 Pirmohamed M, Breckenridge AM, Kitteiingham NR, Park BK (1998) Fortnightly review -adverse drug reactions. BMJ 316 1295-1298... 

The true incidence of allergic sensitization due to cephalosporins alone is difficult to assess, since in most patients treated with cephalosporins, the immune status for penicillin sensitivity before treatment is not objectively known and assessed. The general clinical impression is that in patients sensitized to benzyl-penicillin, overt allergic clinical reactions do not occur in more than 10%-20% of those subsequently treated with cephalosporins. The rate of adverse reactions may, however, be higher than suspected. In healthy volunteers given cephalothin and ce-phapirin intravenously, an unexpectedly high rate of reactions was experienced, and five patients developed skin hypersensitivity detected by skin test with PPL. 

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