What antibiotic is recommended for a patient with a urinary tract infection (UTI) and a urinalysis (UA) positive for yeast and significant bacteriuria, who has an allergy to Penicillin (PCN)?

From the Guidelines

For a patient with a urinary tract infection (UTI) who has a urinalysis positive for yeast and 3+ bacteria and a penicillin allergy, I would recommend ciprofloxacin as the first-line treatment, considering the patient's allergy to penicillin and the potential for complicated UTI, as suggested by the European Association of Urology guidelines 1. The typical dosage is 250-500 mg twice daily for 7-10 days. It's essential to note that ciprofloxacin should only be used if the local resistance rate is <10% and the patient does not require hospitalization, as per the guidelines 1. Alternatives include trimethoprim-sulfamethoxazole (Bactrim) or nitrofurantoin (Macrobid), but ciprofloxacin is preferred in this case due to its effectiveness against a broad range of UTI pathogens, including those that may be resistant to other antibiotics. The presence of yeast in the urine (candiduria) often doesn't require treatment unless the patient is symptomatic for a fungal infection, is immunocompromised, or is undergoing urologic procedures, as suggested by the Infectious Diseases Society of America guidelines 1. Before starting treatment, it would be ideal to obtain a urine culture to guide therapy, especially given the presence of both bacteria and yeast, which could indicate a complicated infection or contaminated sample. Key considerations in managing this patient include:

• The potential for complicated UTI, given the presence of yeast and 3+ bacteria in the urinalysis
• The need to consider local resistance rates when selecting an antibiotic
• The importance of obtaining a urine culture to guide therapy
• The potential for fungal infection, which may require additional treatment, as suggested by the guidelines 1.

From the FDA Drug Label

To reduce the development of drug-resistant bacteria and maintain the effectiveness of sulfamethoxazole and trimethoprim tablets and other antibacterial drugs, sulfamethoxazole and trimethoprim tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. Urinary Tract Infections For the treatment of urinary tract infections due to susceptible strains of the following organisms: Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis and Proteus vulgaris

The patient has a urinary tract infection (UTI) with a urinalysis (UA) positive for yeast and 3+ bacteria. Given the patient's allergy to penicillin (PCN), an alternative antibiotic is needed.

• Trimethoprim-sulfamethoxazole is effective against susceptible strains of bacteria that cause UTIs, including Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis, and Proteus vulgaris 2.
• Levofloxacin is also effective against UTIs, including complicated UTIs and acute pyelonephritis, with bacteriologic eradication rates of 75% or higher for various pathogens 3. Considering the patient's allergy to PCN and the absence of a culture recommendation, levofloxacin or trimethoprim-sulfamethoxazole could be considered as alternative treatment options for the UTI. However, without culture and susceptibility information, it is difficult to determine the most effective treatment. Given the information available, levofloxacin may be a suitable option for treating the UTI, as it has a broad spectrum of activity against various pathogens, including those that cause UTIs 3.

From the Research

Treatment Options for UTI

Given the patient's allergy to PCN (Penicillin), the following treatment options can be considered:

• Nitrofurantoin: a 5-day course is recommended as a first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 4
• Fosfomycin tromethamine: a 3-g single dose is recommended as a first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 4
• Pivmecillinam: a 5-day course is recommended as a first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 4

Considerations for Antibiotic Resistance

It is essential to consider the local susceptibility patterns and the risk of antibiotic resistance when selecting an antibiotic:

• High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin have been reported, making them less suitable as empiric treatment options 4, 5
• Fluoroquinolones, such as levofloxacin and ciprofloxacin, have been compared in terms of efficacy and safety, with no significant difference found between the two 6

Patient-Specific Considerations

The patient's allergy to PCN should be taken into account when selecting an antibiotic:

• Cross-reactivity between penicillin and cephalosporin drugs occurs in about 2% of cases, making it essential to evaluate the patient's allergy history before prescribing a cephalosporin 7
• Direct amoxicillin challenge or penicillin skin testing may be necessary to determine the patient's true allergy status 7