Antibiotics for Strep Throat (Streptococcal Pharyngitis)

Based on "Principles and Practice of Infectious Diseases"
written by John E. Bennett, MD

Updated according to 2012 IDSA Updated Guideline for Managing Group A Streptococcal Pharyngitis 9.

Best Antibiotics for Strep Throat


choice of antibiotic for strep throat infographic

The best antibiotic should provide an optimal balance between effectiveness, safety, cost, and convenience.

Do you need antibiotic for strep throat?

Current Infectious Diseases Society of America (IDSA) guidelines recommend to make a test named confirmatory throat culture before prescribing an antibiotic4. Generally, if the diagnosis of strep throat is confirmed, the doctor will likely prescribe you an antibiotic.

Antibiotic therapy can be started immediately (without testing) when:

  • Patient is very ill
  • Culture results will be delayed for more than 72 hours
  • Patient follow-up will be difficult

Benefits of antibiotics in the treatment of strep throat:

  • Kill the bacteria and shorten the time the patient is contagious. This makes infection less likely to be transmitted to close contacts.
  • Prevent possible complications.
  • Accelerate the resolution of symptoms and hasten healing.

You may want to learn about side effects associated with antibiotics.

Further you will learn about antibiotics approved for strep throat treatment with dosage recommendations and get comprehensive knowledge for wise use of medications.

Antibiotics differ in their bacteriologic and clinical efficacy, dosage frequency, duration of therapy, potential side effects and allergies, compliance and cost.



  • Well-proven excellent efficacy and safety. According to the recent research8, Penicillin is still considered the best choice to treat streptococcal pharyngitis (for those non-allergic to penicillins) in both adults and children. For more than 60 years penicillin retains its ability to kill group A streptococci.
  • Penicillin has a narrow-spectrum and so does not promote antimicrobial resistance.

Penicillin V dosage:9

  • Children: 250 mg two or three times daily for 10 days.
  • Adults: 500 mg twice daily or 250 mg 4 times daily for 10 days.

Benzathine penicillin G (intramuscular)

When a patient is unlikely to complete the full course of oral antibiotic or cannot swallow oral medication, a single dose of intramuscular penicillin G benzathine (Bicillin L-A) is an appropriate option.

Benzathine penicillin G dosage:15

  • <27 kg: 600 000 U, 1 dose
  • ≥27 kg: 1 200 000 U, 1 dose

Why Penicillin may not work?

  • Despite very high susceptibility of Group A Streptococcus to penicillin, the its failure may occur due to beta-lactamase production by oral bacteria12.
  • Penicillin alone may be ineffective for eliminating chronic pharyngeal streptococcal carriage.


Amoxicillin has a broader spectrum than penicillin. However, amoxicillin has no microbiological advantage over the less expensive penicillin.


  • More convenient treatment regimen. Some studies show that amoxicillin given just once a day may work as well as penicillin V given more often.
  • Amoxicillin suspensions taste better than penicillin V suspensions.


  • Gastrointestinal side effects and skin rash are more common with amoxicillin.

Amoxicillin dosage:

  • Children: 50 mg/kg (maximum 1,000 mg) once daily; or alternatively 25 mg/kg (maximum 500 mg) twice daily for 10 days9.
  • Adults: 500 mg three times daily for 10 days.

Amoxicillin/Clavulanate Potassium (Augmentin®)


  • Amoxicillin-clavulanate is resistant to degradation from beta-lactamase produced by pathogens that may colonize the tonsils and pharynx.
  • Amoxicillin-clavulanate is an effective treatment for recurrent streptococcal pharyngitis and chronic pharyngeal carriage of group A streptococci9.


  • Its major adverse effect is diarrhea.

Amoxicillin/Clavulanate Potassium dosage:

  • Children: 40 mg amoxicillin per kg per day, in two or three divided doses for 10 days (maximum 2,000 mg amoxicillin per day)9.
  • Adults: 500 to 875 mg two times daily for 10 days.

Azithromycin (Zithromax Z-Pak®)

Azithromycin, a macrolide antibiotic, is an effective treatment for group A streptococcal pharyngitis and is considered a second-line therapy.


  • Reasonable choice for patients allergic to penicillins.
  • May cure streptococcal infections that fail treatment with penicillins 2.
  • Azithromycin achieves high tonsillar tissue concentrations.
  • Very simple and short once-daily dosing, particularly suitable for persons unwilling to a 10-day antibiotic regimen.
  • Relatively low risk of gastrointestinal side effects.


  • Increasing bacterial resistance 13.

Azithromycin dosage (5-day course):

  • Children: The recommended dosage is 12 mg/kg once daily for 5 days. Or, alternatively, 20 mg/kg once daily for 3 days. (maximum 500 mg per day)9.
  • Adults: The recommended dosage is 500 mg as a single dose on the first day, followed by 250 mg once daily for 4 days 1.

Clarithromycin (Biaxin®)


  • Good choice for patients allergic to penicillin.
  • Very effective. One study suggests that 10 days of clarithromycin may be more effective in eradicating group A streptococci than 5 days of azithromycin 10.


  • Increasing bacterial resistance 13.

Clarithromycin dosage:

  • Children: 7.5 mg/kg/dose twice daily for 10 days (maximum 250 mg per dose)9.
  • Adults: 250 mg every 12 hours for 10 days.

Clindamycin (Cleocin®)


  • Very low resistance. Clindamycin resistance among Group A Streptococcus isolates in the United States is approximately 1%.
  • Clindamycin is a reasonable drug of choice for treating penicillin-allergic patients 4.
  • Clindamycin is very effective for streptococcal pharyngotonsillitis resistant to penicillin 11, as well as for chronic pharyngeal carriage of group A beta-hemolytic streptococci 14.


  • Commonly causes diarrhea.

Clindamycin dosage:

  • Children: 7 mg per kg per dose 3 times daily for 10 days (maximum 300 mg per dose)9.
  • Adults: 300 mg 3 times daily for 10 days.


Cephalosporins are superior to penicillin for relapse and recurrent infections.

Clinical research shows that a 10-day course of a cephalosporin antibiotic is superior to penicillin in eradicating group A beta-hemolytic streptococci 5. Narrower-spectrum cephalosporins such as cefadroxil or cephalexin are preferable to the broader-spectrum cephalosporins such as cefaclor, cefuroxime, cefixime, and cefpodoxime.

Cephalexin (Keflex®)


  • Very effective 5.
  • Superior for relapse and recurrent infections.
  • Cephalexin has a relatively narrow-spectrum and therefore is preferable to the broader-spectrum cephalosporins such as cefaclor, cefuroxime, cefixime, and cefpodoxime.


  • Frequent dosing.

Cephalexin dosage:

  • Children: 20 mg per kg per dose two times for 10 days (maximum 500 mg per dose)9.
  • Adults: 500 mg two times daily for 10 days; or 250 mg four times per day.

Cefadroxil (Duricef®)


  • Effective.
  • Convenient once daily dosing.
  • Low incidence of gastrointestinal side effects.
  • Suspension has a good taste.

Cefadroxil dosage:

  • Children: 30 mg/kg once daily for 10 days (maximum 1 g) 9.
  • Adults: 1 g daily as a single dose or in 2 divided doses for 10 days.


Cefuroxime axetil (Ceftin®)


  • Very effective.
  • Safe for children and pregnant women (pregnancy category B).


  • Unnecessarily broad antibacterial spectrum. IDSA Practice Guidelines 9 don't recommend cefuroxime axetil because narrow-spectrum cephalosporins (cefadroxil or cephalexin) are preferred.

Cefuroxime axetil dosage:

  • Adults and adolescents (13 years and older): 250 mg two times daily for 10 days.
  • Currently, the recommended course of cefuroxime for strep throat is 10 days. However, clinical studies 6-7 demonstrate that short course (4-5 day) of cefuroxime axetil effectively eradicates the infection and prevents post-streptococcal sequelae.
  • Short course of cefuroxime axetil (20 mg/kg/day, max. 500 mg, in two divided doses for 5 days) is effective for treating children aged 1-17 years with streptococcal tonsillopharyngitis 6.

Cefdinir (Omnicef®)


  • Potent antistreptococcal activity.
  • Safe for children and pregnant women (pregnancy category B).
  • Cefdinir provides a slightly higher eradication rate of group A streptococcus bacteria than penicillin V 3.


  • Unnecessarily very broad antibacterial spectrum. IDSA Practice Guidelines 9 don't recommend cefdinir because narrow-spectrum cephalosporins (cefadroxil or cephalexin) are preferred.

Cefdinir dosage:

  • The FDA has approved a 5-day course of Cefdinir for the treatment of streptococcal pharyngitis.

Antibiotics NOT working for strep throat

This list will help you to avoid medical errors. Antibiotics NOT recommended for streptococcal pharyngitis:

  • Metronidazole - not active against Streptococcus pyogenes.
  • Trimethoprim-Sulfamethoxazole (Co-trimoxazole, Bactrim, Bactrim DS) - does not reliably eradicate pharyngeal infection.
  • Tetracyclines - the high prevalence of resistant Streptococcus pyogenes strains.
  • Fluoroquinolones (ciprofloxacin, levofloxacin) - are expensive and have an unnecessarily broad spectrum of activity.

Over-the-counter antibiotics

Many people are wondering if there are any over-the-counter (OTC) antibiotics? Currently, OTC oral antibiotics are not approved in the U.S.

Further reading


  • 1. Hooton TM. A comparison of azithromycin and penicillin V for the treatment of streptococcal pharyngitis. Am J Med. 1991 Sep 12;91(3A):23S-26S. PubMed
  • 2. Cohen R, Reinert P, De La Rocque F, Levy C, Boucherat M, Robert M, Navel M, Brahimi N, Deforche D, Palestro B, Bingen E. Comparison of two dosages of azithromycin for three days versus penicillin V for ten days in acute group A streptococcal tonsillopharyngitis. Pediatr Infect Dis J. 2002 Apr;21(4):297-303. PubMed
  • 3. Tack KJ, Henry DC, Gooch WM, Brink DN, Keyserling CH. Free in PMC Five-day cefdinir treatment for streptococcal pharyngitis. Cefdinir Pharyngitis Study Group. Antimicrob Agents Chemother. 1998 May;42(5):1073-5. PubMed
  • 4. Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America. PDF
  • 5. Casey JR, Pichichero ME. Meta-analysis of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis in children. Pediatrics. 2004 Apr;113(4):866-82. PubMed
  • 6. Scholz H. Streptococcal-A tonsillopharyngitis: a 5-day course of cefuroxime axetil versus a 10-day course of penicillin V. results depending on the children's age. Chemotherapy. 2004 Apr;50(1):51-4.
  • 7. Adam D, Scholz H, Helmerking M. J Antimicrob Chemother. 2000 Feb;45 Suppl:23-30.
  • 8. van Driel ML, De Sutter AI, Habraken H, Thorning S, Christiaens T. Different antibiotic treatments for group A streptococcal pharyngitis. Cochrane Database Syst Rev. 2016 Sep 11;9:CD004406. PubMed
  • 9. Randel A; Infectious Disease Society of America. IDSA Updates Guideline for Managing Group A Streptococcal Pharyngitis. Am Fam Physician. 2013 Sep 1;88(5):338-340. PDF
  • 10. Kaplan EL, Gooch IW, Notario GF, Craft JC. Macrolide therapy of group A streptococcal pharyngitis: 10 days of clarithromycin is more effective in streptococcal eradication than 5 days azithromycin. Clin Infect Dis 2001;32:1798-802.
  • 11. Orrling A, Stjernquist-Desatnik A, Schalén C, Kamme C. Clindamycin in persisting streptococcal pharyngotonsillitis after penicillin treatment. Scand J Infect Dis. 1994;26(5):535-41. PubMed
  • 12. Brook I, Gober AE. Failure to eradicate streptococci and beta-lactamase producing bacteria. Acta Paediatr. 2008 Feb;97(2):193-5. PubMed
  • 13. Logan LK, McAuley JB, Shulman ST. Macrolide treatment failure in streptococcal pharyngitis resulting in acute rheumatic fever. Pediatrics. 2012 Mar;129(3):e798-802.
  • 14. Tanz RR, Poncher JR, Corydon KE, Kabat K, Yogev R, Shulman ST. Clindamycin treatment of chronic pharyngeal carriage of group A streptococci J Pediatr. 1991 Jul;119(1 Pt 1):123-8
  • 15. Group A Streptococcal (GAS) CDC

Published: October 01, 2009
Last updated: August 14, 2018

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