From the Guidelines
Penicillin or ampicillin are the recommended antibiotics for treating Beta-hemolytic Streptococcus group B (GBS) urinary tract infection, with a typical regimen being amoxicillin 500 mg three times daily for 5-7 days, or penicillin V 500 mg four times daily for 5-7 days. These antibiotics are considered the drugs of choice for treating beta-hemolytic streptococcal infections because they inhibit cell wall synthesis in the bacteria, leading to cell death 1. For patients with a penicillin allergy, alternatives include cephalexin 500 mg four times daily or clindamycin 300 mg four times daily for the same duration. It's essential to note that the choice of antibiotic should be guided by the patient's allergy status and the susceptibility of the GBS isolate. According to the CDC guidelines, women with GBS isolated from the urine in any concentration during pregnancy should receive intrapartum chemoprophylaxis, and those with symptomatic or asymptomatic GBS urinary tract infection detected during pregnancy should be treated according to current standards of care for urinary tract infection during pregnancy 1.
Some key points to consider when treating GBS urinary tract infections include:
- The importance of clinical correlation with symptoms to confirm the diagnosis, especially with low colony counts
- The need to consider the patient's penicillin allergy status when selecting an antibiotic
- The recommendation to use penicillin or ampicillin as the first-line treatment for GBS urinary tract infections
- The availability of alternative antibiotics, such as cephalexin or clindamycin, for patients with penicillin allergies
- The importance of following current guidelines and standards of care for treating urinary tract infections during pregnancy 1.
In terms of specific treatment regimens, the CDC guidelines recommend penicillin G, 5 million units intravenously initial dose, then 2.5 million units intravenously every 4 hours until delivery, or ampicillin, 2 g intravenously initial dose, then 1 g intravenously every 4 hours until delivery, for women without penicillin allergy 1. For women with penicillin allergy, the guidelines recommend cefazolin, 2 g intravenously initial dose, then 1 g intravenously every 8 hours until delivery, or clindamycin, 900 mg intravenously every 8 hours until delivery, depending on the patient's allergy status and the susceptibility of the GBS isolate 1.
From the FDA Drug Label
In cases of β-hemolytic streptococcal infections, treatment should continue for at least 10 days. The appropriate antibiotic for Beta-hemolytic Streptococcus, group B (GBS) urinary tract infection is clindamycin.
- The dosage is as follows:
- Adults: 150 to 300 mg every 6 hours for serious infections, and 300 to 450 mg every 6 hours for more severe infections.
- Pediatric Patients: 8 to 16 mg/kg/day divided into three or four equal doses for serious infections, and 16 to 20 mg/kg/day divided into three or four equal doses for more severe infections. 2