Is Bicillin Used for Strep Throat?
Yes, Bicillin—specifically Bicillin L-A (penicillin G benzathine)—treats strep throat caused by group A Streptococcus. It's a long-acting intramuscular penicillin injection recommended by CDC and IDSA guidelines for patients who can't reliably take oral antibiotics, such as children or those with recurrent infections. A single dose provides coverage for 3-4 weeks, killing bacteria by disrupting cell wall synthesis.[1][2]
How Does Bicillin Compare to Oral Antibiotics for Strep?
Bicillin L-A is preferred over oral penicillin V or amoxicillin in cases of poor adherence, vomiting, or noncompliance, with similar cure rates around 90%. Oral options are first-line for most due to easier administration, but Bicillin reduces follow-up doses. It's not for immediate relief—pain meds and supportive care are needed alongside.[3]
What Strains of Strep Does Bicillin Treat?
Effective against beta-hemolytic streptococci, primarily group A (Streptococcus pyogenes), the main cause of strep pharyngitis. It also covers some group B and C/G strains but isn't first-line for non-pharyngitis infections like endocarditis (where Bicillin C-R or IV penicillin is used). Resistance is rare (<1% in the US).[1][4]
When Is Bicillin Prescribed for Strep?
Doctors use it for:
- Confirmed group A strep via rapid test or culture.
- Recurrent strep (3+ episodes/year).
- Outbreaks or close contacts.
- Allergies to other classes (then alternatives like azithromycin).
Avoid in penicillin-allergic patients—risk of anaphylaxis.[2][5]
What Are Common Side Effects and Risks?
Injection site pain (most frequent), fever, or rash occur in 10-20%. Rare serious risks include anaphylaxis (0.01%) or Jarisch-Herxheimer reaction. Not for viral sore throats—overuse promotes resistance. Safe in pregnancy (category B).[3][6]
Dosage and How It's Given for Strep
Adults/children over 27kg: 1.2 million units IM once. Under 27kg: 600,000 units. Given deep in buttock or thigh by healthcare provider—never IV or orally.[1]
Sources
[1]: CDC Strep Throat Guidelines
[2]: IDSA Strep Pharyngitis Guidelines
[3]: Pfizer Bicillin L-A Prescribing Info
[4]: UpToDate: Treatment of Streptococcal Pharyngitis
[5]: AAFP Strep Management
[6]: Medscape Bicillin Dosing