Treatment of Streptococcal Pharyngitis in First Trimester of Pregnancy
Penicillin is the first-line treatment for streptococcal pharyngitis (strep throat) during the first trimester of pregnancy. 1, 2
First-Line Treatment Options
- Penicillin G is the preferred agent for streptococcal pharyngitis during pregnancy due to its narrow spectrum of activity, high efficacy against Group B Streptococcus (GBS), and established safety profile in pregnancy 1, 2
- For outpatient treatment of strep throat, oral penicillin V is appropriate and safe during the first trimester 3, 4
- Ampicillin is an acceptable alternative to penicillin with similar efficacy and safety profile during pregnancy 2, 5
- The full prescribed course of antibiotics must be completed (typically 10 days) to ensure complete eradication and prevent sequelae of streptococcal disease 3, 5
Treatment for Penicillin-Allergic Patients
- For patients with penicillin allergy who are not at high risk for anaphylaxis (no history of anaphylaxis, angioedema, respiratory distress, or urticaria), cefazolin is the preferred alternative 6, 2
- For patients at high risk for anaphylaxis, clindamycin (900 mg IV every 8 hours) can be used if the isolate is confirmed susceptible 6, 2
- If susceptibility testing is not available or the isolate is resistant to clindamycin, vancomycin (1 g IV every 12 hours) is recommended 6, 1
- Erythromycin is no longer recommended due to increasing resistance rates (up to 20.2%) 2
Medications to Avoid During First Trimester
- Tetracyclines should be strictly avoided during pregnancy, especially after the fifth week, as they are deemed contraindicated 4, 7
- Fluoroquinolones (gyrase inhibitors) are contraindicated during pregnancy due to potential toxicity for the unborn child 4, 7
- Aminoglycosides should not be prescribed at any time during pregnancy due to associated nephrotoxicity and ototoxicity 4
- Azithromycin should not be used as first-line therapy for streptococcal pharyngitis due to increasing resistance and limited data on first-trimester safety 8
Special Considerations for Streptococcal Infections in Pregnancy
- Women with GBS bacteriuria in any concentration during pregnancy should receive intrapartum antimicrobial prophylaxis during labor to prevent early-onset neonatal GBS disease 1
- Susceptibility testing should be performed on GBS isolates from penicillin-allergic patients at high risk for anaphylaxis 1, 2
- Testing for inducible clindamycin resistance is necessary for isolates that are susceptible to clindamycin but resistant to erythromycin 1, 2
Clinical Pearls and Pitfalls
- Untreated streptococcal infections during pregnancy can lead to complications including preterm labor and delivery 4, 9
- Underdosing or premature discontinuation of therapy may lead to treatment failure or recurrence 1, 3
- Group C and G streptococci are commonly found in pregnant women (18.2% colonization rate) and can cause pharyngitis similar to Group A streptococci 9
- Penicillin remains the drug of choice for streptococcal pharyngitis as resistance has not been documented, unlike with other antibiotics 2, 5