Bacterial Pharyngotonsillitis (Including Streptococcal & Diphtheria)

Clinical definition:

Acute inflammation of the pharyngeal wall and tonsils commonly caused by viral pathogens including respiratory viruses and Epstein-Barr virus. Common bacterial etiologies include group A beta-haemolytic Streptococci (S. pyogenes). Common symptoms include sore throat and fever.


Child & Adolescent
Preferred antibiotic choice
Amoxicillin (PO)APowder for oral liquid: 125 mg (as trihydrate)/ 5 mL; 250 mg (as trihydrate)/5 mL; Solid oral dosage form: 250 mg; 500 mg (as trihydrate).50 mg/kg once daily, maximum dose 2 g10 days
Alternative antibiotic choice(s)
Benzathine benzylpenicillin (IM)BPowder for injection: 900 mg benzylpenicillin (=1.2 million units) in 5 mL vial; 1.44 g benzylpenicillin (=2.4 million units) in 5 mL vialBy weight:

o   <27 kg: 600 000 units (375 mg) as a single dose

o   27 kg and above: 1.2 million units (750 mg) as a single dose

Single dose
In case of confirmed drug allergy or medical contraindication
Azithromycin (PO)COral liquid: 200 mg/5 mL. Capsule: 250 mg; 500 mg (anhydrous).10 mg/kg once daily, maximum dose 500 mg daily5 days



A. If a patient cannot tolerate oral antibiotics (e.g. persistent vomiting), IV or IM antibiotics may be considered:

  • Ampicillin (25 mg/kg/dose 6 hourly, Maximum dose: 500 mg 6 hourly), or
  • Ceftriaxone (50 mg/kg/dose once daily, Maximum dose: 1 g daily)

B. Painful IM administration of benzathine benzylpenicillin may be reduced by dissolving benzathine benzylpenicillin 1.2 million units in 3.2 mL lidocaine 1% without adrenaline (epinephrine) and bringing the preparation to room temperature before injection.

C. Significant rates of resistance of Group A Streptococcus strains to macrolides (azithromycin) and azalides (clarithromycin) have been reported in many parts of the world. If patient fails treatment with a macrolide or azalide, consider ceftriaxone or refer to a specialist.


Principles of Stewardship:

  • Clinical features that suggest a viral rather than a bacterial cause of pharyngotonsillitis include runny nose, hoarse voice or cry, cough, conjunctivitis, discrete oral ulcerative lesions, and diarrhoea. In these cases, avoid antibiotic use.
  • Children less than 3 years of age should not receive antibiotics as part of treatment for pharyngotonsillitis as they are not at significant risk for acute rheumatic fever.