From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
For recurrent urinary tract infections (UTIs), cefdinir is typically prescribed at a dose of 300 mg twice daily for 7-10 days, as supported by the most recent study 1. This dose is effective against many common UTI-causing pathogens, including Escherichia coli. However, it's essential to note that cefdinir is not typically a first-line treatment for uncomplicated UTIs; nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin are usually preferred. Cefdinir may be used when these first-line agents are not appropriate due to resistance patterns or patient allergies. Some key points to consider when prescribing cefdinir for UTIs include:
- The importance of completing the full course of antibiotics, even if symptoms improve before finishing the prescription
- The potential need for preventive strategies beyond just treatment for truly recurrent UTIs (defined as 3 or more UTIs within 12 months), including prophylactic antibiotics, vaginal estrogen in postmenopausal women, or behavioral modifications
- The consideration of alternative antibiotics, such as cephalexin, which may have comparable efficacy to cefdinir for the treatment of lower UTIs, as shown in a recent retrospective evaluation 1
- The potential for differences in pharmacokinetics between cefdinir and other cephalosporins, which could result in dissimilar efficacy, although comparative studies are lacking
- The need to adjust the dose of cefdinir in patients with renal impairment (creatinine clearance <30 mL/min) to 300 mg once daily. It's also worth noting that cefdinir has been compared to other antibiotics, such as cefaclor, in the treatment of uncomplicated urinary tract infections, and has shown similar efficacy 2. Overall, cefdinir can be a useful option for the treatment of recurrent UTIs, but its use should be guided by the most recent evidence and individual patient factors.