What is an oral outpatient treatment for group B streptococcus (GBS) bacteriuria in an 83-year-old patient with a penicillin allergy (without anaphylaxis)?

From the Guidelines

For an 83-year-old patient with group B strep (GBS) in the urine who has a non-anaphylactic penicillin allergy, I recommend oral trimethoprim-sulfamethoxazole (TMP-SMX) as the first-line treatment, as it is effective against GBS and has a favorable safety profile in elderly patients without severe penicillin allergies 1. The typical dosage is one double-strength tablet (160 mg TMP/800 mg SMX) twice daily for 5-7 days.

Alternative Treatments

Alternatively, nitrofurantoin 100 mg twice daily for 5-7 days can be used if kidney function is adequate (creatinine clearance >30 mL/min).

• Clindamycin 300 mg orally four times daily for 7 days is another option for patients with more severe penicillin allergies or contraindications to these medications.
• It's essential to monitor for side effects, particularly with TMP-SMX, which can cause electrolyte disturbances and increased risk of hyperkalemia, especially if the patient is on other medications like ACE inhibitors or has reduced kidney function.

Considerations for Elderly Patients

When treating elderly patients, adequate hydration should be encouraged during treatment.

• These antibiotics are effective against GBS because they target different aspects of bacterial metabolism or cell wall synthesis, providing alternatives to penicillin-class antibiotics while still effectively eliminating the infection.
• The choice of antibiotic should be guided by the patient's medical history, current medications, and kidney function to minimize potential adverse effects.

Monitoring and Follow-up

Regular follow-up appointments should be scheduled to monitor the patient's response to treatment and adjust the antibiotic regimen as needed.

• In cases where the patient's condition worsens or does not improve with oral antibiotics, hospitalization and intravenous antibiotic therapy may be necessary.
• It is crucial to weigh the benefits and risks of each treatment option and consider the patient's quality of life, morbidity, and mortality when making decisions about their care.

From the FDA Drug Label

Adults: The usual dose of oral doxycycline is 200 mg on the first day of treatment (administered 100 mg every 12 hours) followed by a maintenance dose of 100 mg/day Syphilis–early: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 2 weeks Syphilis of more than one year’s duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 4 weeks.

For an 83-year-old patient allergic to penicillin without anaphylaxis, doxycycline can be considered as an oral outpatient treatment option. The recommended dose for this patient would be 100 mg orally twice a day. However, it's essential to note that the provided drug labels do not explicitly mention the treatment of group B strep in the urine. Therefore, the use of doxycycline for this specific condition would be off-label. 2

From the Research

Oral Outpatient Treatment for Group B Strep in Urine

For an 83-year-old patient allergic to penicillin without anaphylaxis, the following options can be considered:

• Clindamycin, as it has a relatively low resistance rate of 4% among group B streptococcal isolates 3
• Erythromycin, although it has a higher resistance rate of 21% compared to clindamycin 3
• Other antibiotics such as ciprofloxacin, ofloxacin, or vancomycin may also be considered, but their effectiveness and resistance rates should be evaluated on a case-by-case basis 4, 5

Considerations for Treatment

When selecting an oral outpatient treatment, it is essential to consider the patient's underlying health conditions, potential interactions with other medications, and the severity of the infection.

• The patient's age and potential comorbidities, such as congestive heart failure or being bedridden, should be taken into account when choosing a treatment regimen 6
• The treatment should be tailored to the specific needs of the patient, and close monitoring of the patient's response to treatment is crucial to ensure effective management of the infection 7, 6