What can be prescribed for a 15-year-old female with a urinary analysis (UA) positive for urinary tract infection (UTI), who is allergic to Penicillin (PNC) and weighs 87 pounds, without using Cephalexin (Keflex)?

From the Guidelines

For a 15-year-old female with a urinary tract infection who is allergic to penicillin and whose mother wants to avoid Keflex, I recommend nitrofurantoin (Macrobid) 100 mg twice daily for 5 days. Based on her weight of 87 lbs (approximately 39.5 kg), this is an appropriate dose 1. Alternatively, trimethoprim-sulfamethoxazole (Bactrim) DS tablet twice daily for 3 days would be effective if there are no contraindications. If the patient has symptoms suggesting upper urinary tract involvement (fever, flank pain), consider ciprofloxacin 500 mg twice daily for 7 days, though fluoroquinolones are generally reserved for more severe cases in adolescents due to potential side effects 1. It's essential to ensure adequate hydration during treatment and to complete the full course of antibiotics even if symptoms improve quickly. These medications are effective against common urinary pathogens and represent good alternatives for patients with penicillin allergies who cannot take cephalosporins like Keflex.

Some key points to consider:

• The choice of antibiotic should be based on local resistance patterns and patient-specific factors such as allergy history and tolerance 1.
• Nitrofurantoin and trimethoprim-sulfamethoxazole are effective options for uncomplicated urinary tract infections, with nitrofurantoin being a good choice for patients with penicillin allergies 1.
• Ciprofloxacin is a viable option for more severe cases or upper urinary tract involvement, but its use should be judicious due to potential side effects and resistance patterns 1.
• It's crucial to complete the full course of antibiotics and ensure adequate hydration to prevent treatment failure and reduce the risk of complications 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. In the absence of such data, local epidemiology and susceptibility patterns may contribute to empiric selection of 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 It is recommended that initial episodes of uncomplicated urinary tract infections be treated with a single effective antibacterial agent rather than the combination

For a 15-year-old female with a urinary analysis (UA) positive for urinary tract infection (UTI), who is allergic to Penicillin (PNC) and weighs 87 pounds, trimethoprim-sulfamethoxazole (PO) can be prescribed as an alternative to treat the UTI, without using Cephalexin (Keflex), as it is effective against susceptible strains of bacteria that cause UTIs, such as Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis, and Proteus vulgaris 2.

From the Research

Treatment Options for Urinary Tract Infections (UTIs)

Given the patient's allergy to Penicillin (PNC) and the need to avoid Cephalexin (Keflex), the following treatment options can be considered for a 15-year-old female with a urinary analysis (UA) positive for UTI:

• Nitrofurantoin: This is a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3, 4, 5, 6.
• Fosfomycin: This is also a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3, 7.
• Pivmecillinam: This is another recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3, 7.
• Amoxicillin-clavulanate: This can be considered as a second-line option, but its use should be guided by local susceptibility patterns and the patient's allergy history 3, 5.

Considerations for Treatment

When selecting a treatment option, it is essential to consider the patient's weight, age, and allergy history. The patient's weight of 87 pounds should be taken into account when determining the appropriate dosage of the selected antibiotic.

• The patient's allergy to Penicillin (PNC) should be considered when selecting a treatment option, and Cephalexin (Keflex) should be avoided 3, 5, 6.
• Local susceptibility patterns and resistance rates should also be considered when selecting a treatment option 3, 4, 5, 6.

Antibiotic Susceptibility Patterns

The susceptibility patterns of common uropathogens, such as Escherichia coli, Klebsiella pneumoniae, and Group B Streptococcus, should be considered when selecting a treatment option 5.

• Nitrofurantoin has been shown to be effective against Escherichia coli, with a susceptibility rate of 96.9% 5.
• Cefpodoxime and ceftriaxone have also been shown to be effective against common uropathogens, with susceptibility rates of 94% and 85.4%, respectively 5, 6.