A Phase 4 interventional study of Doxycycline and Azithromycin in Community-acquired Pneumonia, sponsored by Mayo Clinic. Recruiting at 5 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-24.
Sponsored by Mayo Clinic · Phase 4, Interventional, and Treatment
The purpose of this study is to compare effectiveness and safety of Azithromycin versus Doxycycline in adult patients hospitalized with community acquired pneumonia (CAP) treated with Beta-lactams.
324 studies on the registry are indexed under Community-Acquired Pneumonia; 77 are open to participants now.
This study's planned enrollment of 1,120 is above the median of 250 across 195 interventional studies indexed under Community-Acquired Pneumonia.
Browse Community-Acquired Pneumonia studies →Mayo Clinic is the lead sponsor of 3,269 studies on the registry; 672 are open to participants now.
Of its 452 completed or terminated interventional studies of FDA-regulated products, 321 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Subjects hospitalized for community acquired pneumonia will receive standard of care treatment with Doxycycline
Drug: Doxycycline
Subjects hospitalized for community acquired pneumonia will receive standard of care treatment with Azithromycin
Drug: Azithromycin
Subjects will receive Doxycycline (orally or intravenously) in combination with beta-lactam therapy within 12 hours of hospital admission. Treatment duration will be determined by treating clinician (5-7 days per guidelines).
Subjects will receive Azithromycin (orally or intravenously) in combination with beta-lactam therapy within 12 hours of hospital admission. Treatment duration will be determined by treating clinician (5-7 days per guidelines).
Days alive and out of hospital
Days alive spent outside of the hospital, within 28 days of randomization
Time frame: 28 days
Oxygen-free days
Number of days subject does not require new supplemental oxygen use. Oxygen-free days will be set as 0 for patients who died during the stay or had a length of stay of ≥28 days
Time frame: 28 days
Need for advanced respiratory support or in-hospital mortality
Defined as a composite of need for advanced respiratory support or mortality during hospitalization. Need for advanced respiratory support would include need for high flow nasal cannula, non-invasive positive pressure ventilation, and invasive ventilation in patients not requiring this at baseline.
Time frame: 28 days
Need for Advanced Respiratory Support
Need for advanced respiratory support including invasive mechanical ventilation, non-invasive mechanical ventilation, high flow nasal cannula,
Time frame: 28 days
In-Hospital Mortality
Mortality during hospitalization
Time frame: 28 days
Ordinal clinical status scale
Change from baseline on an ordinal clinical status scale from hospitalized, not requiring supplemental oxygen, to death
Time frame: 28 days
60-day Mortality
Defined as mortality at 60 days after discharge
Time frame: 60 days post discharge
180-day mortality
Defined as mortality at 180 days after discharge
Time frame: 180 days
Incident Clostridioides difficile infection
Positive stool antigen test, will only be assessed when testing is ordered as part of routine clinical care
Time frame: 28 days
New arrhythmias requiring intervention and/or QT prolongation
Outcome will only be assessed when an ECG is ordered as part of routine clinical care
Time frame: 28 days
Plan to share: Yes — De-identified individual participant data and the accompanying data dictionary will be made available in a secure, controlled-access data repository within one year of publication. Statistical code (R scripts) and supporting documentation will be shared via GitHub to enable transparency and reproducibility.
Supporting information: Study protocol, Analytic code
Time frame: Within one year after publication of the primary results manuscript.
Access criteria: Qualified investigators may request access to the de-identified data under a data use agreement.
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Studies of the drugs tested here: Doxycycline · Azithromycin
Community-Acquired Pneumonia →