The aim of this randomised controlled trial is to identify the optimal treatment duration with phenoxymethylpenicillin for community-acquired pneumonia diagnosed in general practice.

Eligible participants are adults (≥18 years) presenting in general practice with symptoms of an acute LRTI (i.e., acute illness (≤ 21 days) usually with cough and minimum one other symptom such as dyspnea, sputum production, wheezing, chest discomfort or fever) in whom the GP finds it relevant to treat with antibiotics.

Consenting patients who meet all the eligibility criteria will be randomised (1:1:1:1:1) to either three, four, five, six or seven days of treatment with phenoxymethylpenicillin 1.2 MIE four times daily.

Inclusion Criteria:

Eligible participants are adults (≥18 years) presenting in general practice with symptoms of an acute LRTI (i.e., acute illness (≤ 21 days) usually with cough and minimum one other symptom such as dyspnoea, sputum production, wheezing, chest discomfort or fever) in whom the GP finds it relevant to treat with antibiotics.

Exclusion Criteria:

1. Need for immediate hospitalisation at the time of diagnosis.
2. Known allergy to beta-lactam antibiotics.
3. Any coinfection necessitating antibiotic treatment.
4. Use of systemic antibiotics or antivirals within the last month.
5. Pre-existing lung disease (e.g., chronic obstructive pulmonary disease, bronchiectasis, asthma, lung cancer).
6. Known immunosuppression (i.e., long term treatment with corticosteroid, chemotherapy, or immune disorder).
7. Pregnant or lactating.
8. Patients not capable of consenting and/or patients deemed non-suitable for participation by the healthcare professional.