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To document a suspected reaction to an antimicrobial drug
Penicillins are some of the most frequently prescribed antibiotics in clinical practice. The following list includes the penicillins available in Australia, and the common brand names:
A history of penicillin allergy should not rule out the use of cephalosporins. The prevalence of cross-reactivity between beta-lactams is lower than originally thought. An estimated 1-2% of patients with a penicillin allergy react to cephalosporins. 1
Antibiotics with shared structural similarities, such as those with the same or similar R1-group side-chains are more likely to cross-react:
In patients with a history of delayed severe penicillin hypersensitivity [e.g. drug rash with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome/Toxic epidermal necrolysis (SJS/TEN), Acute generalised exanthematous pustulosis (AGEP)], avoid all penicillins and cephalosporins – Do not use cross-reactivity to guide treatment as further drug exposure can be fatal.
An algorithm for the suggested management of patients reporting a hypersensitivity to penicillins in whom a beta-lactam is the preferred drug is available in the Therapeutic Guidelines:Antibiotic2:
Many patients who believe they have a ‘penicillin allergy’ are not allergic when tested. Testing involves initial risk stratification based on history and available information, with subsequent either direct de-labelling, oral challenge testing (in low risk cases), or skin testing followed by oral challenge if negative (in higher risk cases). 7 Some patients are confirmed to be allergic either by available information, or after testing.
In patients with a confirmed beta-lactam allergy, or those who have a high-risk history when there is no opportunity for testing, desensitisation can be attempted under specialist care, which will allow temporary tolerance of the antibiotic.
Prioritisation for testing and potential de-labelling will take into account the likely antibiotic requirements of the patient including factors such as:
History of bacterial infection and antibiotic requirement in the recent past
The National Antibiotic Allergy Network (NAAN) has developed guidance for clinicians on antibiotic allergy assessment and management of an oral antibiotic challenge in patients who have an antibiotic allergy.
The National Antibiotic Allergy Network (NAAN) has developed these patient information leaflets:
Patients can also use this Antibiotic Allergy Alert Card
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