One-time IV penicillin added to standard penicillin for adults with acute tonsillitis, tonsillitis with peritonsillar phlegmon, or peritonsillar abscess

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This phase 4 trial tests whether adding a single IV dose of benzylpenicillin to usual oral phenoxymethylpenicillin improves outcomes for adults with AT, PP, or PTA treated by incision. Participants receive either the IV antibiotic or a placebo alongside standard care, with measurements focused on pain, symptom burden, analgesic use, complications, and long-term results. The study targets adults without penicillin allergy and seeks to understand if the adjunct reduces treatment failure or progression. The design reflects a pragmatic approach to real-world treatment settings in Denmark. Safety monitoring and ethical considerations are integral components of the protocol.

Why it matters

Who can join: the full rules

Inclusion Criteria:

Participants must meet one of the following clinical criteria:

* Clinically verified acute tonsillitis (AT) with a Centor score of 3-4 and without peritonsillar phlegmon (AT group);
* Clinical acute tonsillitis (AT) with a Centor score of 3-4 and with peritonsillar phlegmon (PP group); or
* Peritonsillar abscess treated by incision (PTA group).

Additionally, participants must meet the following criteria:

* Written informed consent;
* Age ≥18 years.

Exclusion Criteria:

* Known allergy or hypersensitivity to penicillin;
* Pregnancy or planned pregnancy;
* Suspected or confirmed spread of infection, including but not limited to:
* Parapharyngeal or retropharyngeal abscess
* Necrotizing fasciitis
* Mediastinitis
* Lemierre's syndrome.

Where it's running

• Aarhus University Hospital
  Aarhus, Central Jutland, Denmark Recruiting

Study contacts

• Principal investigator: Tejs E Klug, MD, DMSc — Aarhus University Hospital

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.