From the Guidelines
For step B urine coverage in patients allergic to penicillins, I recommend using cefdinir as first-line therapy, as it is highly unlikely to be associated with cross-reactivity with penicillin allergy, according to the most recent and highest quality study 1. This recommendation is based on the fact that the chemical structure of cefdinir determines the risk of cross-reactivity, which is negligible with second- and third-generation cephalosporins, such as cefdinir, cefuroxime, cefpodoxime, and ceftriaxone 1. Some key points to consider when selecting an antibiotic for patients with penicillin allergies include:
- The risk of cross-reactivity between penicillins and cephalosporins is lower than historically reported, with a reaction rate of 0.1% 1
- The severity of the index reaction and the time elapsed since the reaction are important factors in assessing the risk of recurrence of a severe allergic reaction 1
- A systematic approach to estimating the risk of recurrence, including recording a formal allergy history and evaluating the pros and cons of alternative antimicrobial treatments, is essential 1
- Non-beta-lactam options, such as aztreonam or an aminoglycoside like gentamicin, may be considered for patients with severe penicillin allergies who need broader coverage 1 It is also important to consider local resistance patterns, patient-specific factors like renal function, and the severity of infection when selecting an antibiotic. The most recent study 1 supports a more liberal approach towards patients with suspected antibiotic allergy, and the implementation of the recommendations outlined in this guideline may result in the use of smaller spectrum antibiotics with fewer side effects, less toxicity, and potentially lower risks of antibiotic resistance.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Urine Coverage for Allergic to Penicillins
- For patients allergic to penicillins, several alternative antibiotics can be used to treat urinary tract infections (UTIs) 2, 3.
- First-line options include nitrofurantoin, fosfomycin, and pivmecillinam, which have been shown to be effective against common uropathogens 2, 3.
- Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones, and β-lactams such as amoxicillin-clavulanate, although their use may be limited by resistance patterns 2.
- For patients with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales, treatment options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 2.
Treatment Options for Specific Types of UTIs
- For UTIs caused by ESBLs-E coli, treatment options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 2.
- For UTIs caused by ESBLs-Klebsiella pneumoniae, treatment options include pivmecillinam, fosfomycin, finafloxacin, and sitafloxacin 2.
- For UTIs caused by carbapenem-resistant Enterobacteriales (CRE), treatment options include ceftazidime-avibactam, meropenem/vaborbactam, imipenem/cilastatin-relebactam, colistin, fosfomycin, aztreonam, and cefiderocol 2.
Comparative Effectiveness of Antibiotics
- A network meta-analysis of randomized trials found that ciprofloxacin and gatifloxacin were the most effective treatments for UTIs, while amoxicillin-clavulanate was the least effective 4.
- Another study found that nitrofurantoin was at least comparable to other common UTI treatments in terms of clinical and bacteriological cure 5.