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Combination Antibiotic Treatment for Reactive Arthritis Caused by Chlamydia Bacteria

Phase 3 Trial to Assess the Efficacy of Long-term (6 Months) Combination Antibiotics as a Treatment for Chlamydia-induced Reactive Arthritis

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00351273
Enrollment
42
Registered
2006-07-12
Start date
2006-05-31
Completion date
2008-09-30
Last updated
2018-11-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Arthritis, Reactive, Reiter Disease

Keywords

Chlamydia

Brief summary

Reactive arthritis, also known as Reiter's syndrome, is a form of arthritis that occurs as a reaction to an infection elsewhere in the body. It is characterized by inflammation of the joints, tendons, urogenital tract, and eyes. Pain and swelling in the knees, ankles, and feet are common. This study will determine the effectiveness of antibiotic therapy in treating people with chlamydia-induced reactive arthritis that has lasted for more than 6 months.

Detailed description

The initial infection that causes reactive arthritis is caused by one of two bacteria: Chlamydia trachomatis, which is usually acquired through sexual contact, or Chlamydia pneumoniae, which can cause respiratory infections. Most people recover fully from the initial flare of arthritis symptoms. However, about 20% of people with reactive arthritis experience long-lasting symptoms. In these individuals, the Chlamydia bacteria exist in a persistent metabolically active state within the joint tissue, even years after the initial exposure. The bacteria produce heat shock proteins (HSPs), which are thought to play a key role in the chronic persistent state of Chlamydia and which may stimulate the immune inflammatory response seen in reactive arthritis. This indicates the need for antimicrobial therapy that can reduce Chlamydia's HSP production and block its metabolism. The purpose of this study is to determine the effectiveness of long-term combination antibiotic therapy in treating people with chronic reactive arthritis. The study will use two different combinations of common antibiotics: doxycycline paired with rifampin and azithromycin paired with rifampin. This study will entail 6 months of treatment followed by 3 months of follow-up. After screening, eligible participants will be randomly assigned to one of three treatment groups: rifampin once a day plus doxycycline twice a day; rifampin once a day plus azithromycin once a day for 5 days, then twice weekly; or placebo. Study visits will occur at baseline and Months 1, 3, 6, and 9. At all visits, participants will undergo an interview, a physical examination, and blood collection. They will also complete a questionnaire related to their symptoms and functional status. At screening and Month 6, a synovial biopsy may be performed. This will involve taking a sample of the tissue that lines the joints.

Interventions

DRUGDoxycycline and Rifampin

doxycycline 100mg daily; rifampin 300mg daily (both for 6 months)

DRUGAzithromycin and Rifampin

Azithromycin 500mg daily for 5 days and then twice weekly; Rifampin 300mg daily (both for 6 months)

DRUGPlacebo

Methylcellulose

Sponsors

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
CollaboratorNIH
University of South Florida
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

* Meet the following European Spondyloarthropathy Study Group Criteria: 1. inflammatory spinal pain OR 2. synovitis AND 3. one or more of the following: 1. positive family history 2. urethritis or cervicitis within 1 month prior to onset of arthritis 3. buttock pain 4. enthesopathy 5. sacroiliitis * Disease duration of at least 6 months * Negative pregnancy test at study baseline and willing to use an effective method of contraception other than combined oral contraceptives for the duration of the study (for women of childbearing age)

Exclusion criteria

* Sensitivity or history of allergic reaction to rifampin, doxycycline, or azithromycin * Currently taking any medications that may interact with the study medications, specifically rifampin * Liver transaminases greater than or equal to two times the normal level * Significant abnormalities in the complete blood count (CBC) * Pregnant * Current psoriasis * Diagnosis of inflammatory bowel disease * Diagnosis of ankylosing spondylitis * Previous prolonged exposure to antibiotics (more than 2 weeks) as a potential treatment for reactive arthritis

Design outcomes

Primary

MeasureTime frameDescription
Investigate Whether a 6 Month Course of Combined Antibiotics Was Effective Treatment.Month 6The outcome measure was a composite endpoint. Participants had to meet 4/6 clinical criteria. 17/24 subjects randomized to combination antibiotics did respond to treatment when compared to 3/10 randomized to placebo.

Secondary

MeasureTime frameDescription
Erythrocyte Sedimentation Rate (ESR)Baseline Month 1, 3, 6 and 9Comparison of mean ESR rates of combination antibiotic group vs placebo group at Baseline, Month 1, 3, 6 and 9
hsCRPBaseline, Month 1, 3, and 6Comparison of high sensitivity C-reactive protein measurement in combination antibiotic group vs placebo group at Baseline, Month 1, 3, and 6
HAQ DI ScoreBaseline, Month 1,3,6 and 9Comparison of HAQ-DI score of combination antibiotic group vs placebo group at Baseline, Month 1,3,6 and 9 The Health assessment questionnaire disability index (HAQ-DI) is a questionnaire for the assessment of Rheumatoid Arthritis. The questionnaire is a patient reported outcome (PRO) which is usually self-administered by the patient There are 8 sections: dressing, arising, eating, walking, hygiene, reach, grip, and activities. There are 2 or 3 questions for each section. Scoring within each section is from 0 (without any difficulty) to 3 (unable to do). For each section the score given to that section is the worst score within the section, i.e. if one question is scored 1 and another 2, then the score for the section is 2. In addition, if an aide or device is used or if help is required from another individual, then the minimum score for that section is 2. If the section score is already 2 or more then no modification is made. The 8 scores of the 8 sections are summed and divided
Number of Patients With a Complete Response (Resolution of All Symptoms)Months 6 and 9Patients who completed full 6 months of treatment that reported feeling complete resolution of symptoms at month 6 visit and had no worsening of condition at the month 9 follow up visit.
Swollen 76 Joint Count (SJC)Baseline, month 1,3,6 and 9Comparison of modified Swollen Joint Counts between combination antibiotic and placebo groups at Baseline, Month 1, 3, 6 and 9. Determination of swelling in each of the 76 joints was determined by any swelling or absence of swelling. Each swollen joint receives a value of 1, ranging from 0-76 as a possible score.
78 Tender Joint Count (TJC)Baseline, Month 1, 3, 6 and 9Comparison of modified 78 Tender Joint Count (TJC) between combination antibiotic and placebo groups at Baseline, Month 1, 3, 6 and 9. Determination of tender joing in each of the 78 joints was determined by examination. Each tender joint receives a value of 1, ranging from 0-78 as a possible score.
PhGA AssessmentBaseline, month 1,3,6 and 9Comparison of Physician's global assessment of disease activity (PhGA) using 0-100mm visual analog scale (VAS) , where 0 indicates the best possible outcome and 100 indicates the worst possible outcome, in combination antibiotic vs placebo groups at Baseline, month 1,3,6 and 9

Countries

Canada, United States

Participant flow

Participants by arm

ArmCount
Azithromycin & Rifampin
Participants will receive Azithromycin and Rifampin
15
Doxycycline & Rifampin
Participants will receive Doxycycline and Rifampin
12
Placebo
Participants will receive placebo
15
Total42

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall StudyLost to Follow-up125

Baseline characteristics

CharacteristicAzithromycin & RifampinDoxycycline & RifampinPlaceboTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
0 Participants0 Participants2 Participants2 Participants
Age, Categorical
Between 18 and 65 years
15 Participants12 Participants13 Participants40 Participants
Age, Continuous44.5 years
STANDARD_DEVIATION 12
43.8 years
STANDARD_DEVIATION 12.3
49 years
STANDARD_DEVIATION 16.3
45.8 years
STANDARD_DEVIATION 11.5
Region of Enrollment
Canada
0 participants0 participants1 participants1 participants
Region of Enrollment
United States
15 participants12 participants14 participants41 participants
Sex: Female, Male
Female
7 Participants5 Participants6 Participants18 Participants
Sex: Female, Male
Male
8 Participants7 Participants9 Participants24 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —
other
Total, other adverse events
0 / 150 / 120 / 15
serious
Total, serious adverse events
0 / 150 / 120 / 15

Outcome results

Primary

Investigate Whether a 6 Month Course of Combined Antibiotics Was Effective Treatment.

The outcome measure was a composite endpoint. Participants had to meet 4/6 clinical criteria. 17/24 subjects randomized to combination antibiotics did respond to treatment when compared to 3/10 randomized to placebo.

Time frame: Month 6

Population: Efficacy and safety analyses were performed on an intent to treat(ITT) basis. Subjects who prematurely withdrew or who were lose to follow up for any reason were included in the ITT population and were considered nonresponders.

ArmMeasureValue (NUMBER)
Azithromycin & RifampinInvestigate Whether a 6 Month Course of Combined Antibiotics Was Effective Treatment.10 participants
Doxycycline & RifampinInvestigate Whether a 6 Month Course of Combined Antibiotics Was Effective Treatment.7 participants
PlaceboInvestigate Whether a 6 Month Course of Combined Antibiotics Was Effective Treatment.3 participants
Comparison: Difference in the percentages of participants with response between all those who received combination therapy vs. placebop-value: 0.01Fisher Exact
Secondary

78 Tender Joint Count (TJC)

Comparison of modified 78 Tender Joint Count (TJC) between combination antibiotic and placebo groups at Baseline, Month 1, 3, 6 and 9. Determination of tender joing in each of the 78 joints was determined by examination. Each tender joint receives a value of 1, ranging from 0-78 as a possible score.

Time frame: Baseline, Month 1, 3, 6 and 9

ArmMeasureGroupValue (MEAN)
Azithromycin & Rifampin78 Tender Joint Count (TJC)Month 33.3 Tender Joints
Azithromycin & Rifampin78 Tender Joint Count (TJC)Month 62.0 Tender Joints
Azithromycin & Rifampin78 Tender Joint Count (TJC)Month 15.0 Tender Joints
Azithromycin & Rifampin78 Tender Joint Count (TJC)Month 91.9 Tender Joints
Azithromycin & Rifampin78 Tender Joint Count (TJC)Baseline7.4 Tender Joints
Doxycycline & Rifampin78 Tender Joint Count (TJC)Month 910.9 Tender Joints
Doxycycline & Rifampin78 Tender Joint Count (TJC)Baseline9.6 Tender Joints
Doxycycline & Rifampin78 Tender Joint Count (TJC)Month 110.6 Tender Joints
Doxycycline & Rifampin78 Tender Joint Count (TJC)Month 611.8 Tender Joints
Doxycycline & Rifampin78 Tender Joint Count (TJC)Month 310.8 Tender Joints
Secondary

Erythrocyte Sedimentation Rate (ESR)

Comparison of mean ESR rates of combination antibiotic group vs placebo group at Baseline, Month 1, 3, 6 and 9

Time frame: Baseline Month 1, 3, 6 and 9

ArmMeasureGroupValue (MEAN)
Azithromycin & RifampinErythrocyte Sedimentation Rate (ESR)Month 117.8 millimeters/hour
Azithromycin & RifampinErythrocyte Sedimentation Rate (ESR)Month 612.7 millimeters/hour
Azithromycin & RifampinErythrocyte Sedimentation Rate (ESR)Month 317.7 millimeters/hour
Azithromycin & RifampinErythrocyte Sedimentation Rate (ESR)Month 914.0 millimeters/hour
Azithromycin & RifampinErythrocyte Sedimentation Rate (ESR)Baseline25.1 millimeters/hour
Doxycycline & RifampinErythrocyte Sedimentation Rate (ESR)Month 918.4 millimeters/hour
Doxycycline & RifampinErythrocyte Sedimentation Rate (ESR)Baseline18.9 millimeters/hour
Doxycycline & RifampinErythrocyte Sedimentation Rate (ESR)Month 125.2 millimeters/hour
Doxycycline & RifampinErythrocyte Sedimentation Rate (ESR)Month 319.8 millimeters/hour
Doxycycline & RifampinErythrocyte Sedimentation Rate (ESR)Month 617.0 millimeters/hour
Secondary

HAQ DI Score

Comparison of HAQ-DI score of combination antibiotic group vs placebo group at Baseline, Month 1,3,6 and 9 The Health assessment questionnaire disability index (HAQ-DI) is a questionnaire for the assessment of Rheumatoid Arthritis. The questionnaire is a patient reported outcome (PRO) which is usually self-administered by the patient There are 8 sections: dressing, arising, eating, walking, hygiene, reach, grip, and activities. There are 2 or 3 questions for each section. Scoring within each section is from 0 (without any difficulty) to 3 (unable to do). For each section the score given to that section is the worst score within the section, i.e. if one question is scored 1 and another 2, then the score for the section is 2. In addition, if an aide or device is used or if help is required from another individual, then the minimum score for that section is 2. If the section score is already 2 or more then no modification is made. The 8 scores of the 8 sections are summed and divided

Time frame: Baseline, Month 1,3,6 and 9

ArmMeasureGroupValue (MEAN)
Azithromycin & RifampinHAQ DI ScoreMonth 10.79 score on a scale
Azithromycin & RifampinHAQ DI ScoreMonth 60.71 score on a scale
Azithromycin & RifampinHAQ DI ScoreMonth 30.68 score on a scale
Azithromycin & RifampinHAQ DI ScoreMonth 90.57 score on a scale
Azithromycin & RifampinHAQ DI ScoreBaseline0.84 score on a scale
Doxycycline & RifampinHAQ DI ScoreMonth 90.92 score on a scale
Doxycycline & RifampinHAQ DI ScoreBaseline1.1 score on a scale
Doxycycline & RifampinHAQ DI ScoreMonth 10.92 score on a scale
Doxycycline & RifampinHAQ DI ScoreMonth 30.87 score on a scale
Doxycycline & RifampinHAQ DI ScoreMonth 60.99 score on a scale
Secondary

hsCRP

Comparison of high sensitivity C-reactive protein measurement in combination antibiotic group vs placebo group at Baseline, Month 1, 3, and 6

Time frame: Baseline, Month 1, 3, and 6

ArmMeasureGroupValue (MEAN)
Azithromycin & RifampinhsCRPBaseline1.07 mg/litre
Azithromycin & RifampinhsCRPMonth 10.56 mg/litre
Azithromycin & RifampinhsCRPMonth 30.63 mg/litre
Azithromycin & RifampinhsCRPMonth 60.41 mg/litre
Doxycycline & RifampinhsCRPMonth 60.34 mg/litre
Doxycycline & RifampinhsCRPBaseline0.42 mg/litre
Doxycycline & RifampinhsCRPMonth 30.55 mg/litre
Doxycycline & RifampinhsCRPMonth 10.27 mg/litre
Secondary

Number of Patients With a Complete Response (Resolution of All Symptoms)

Patients who completed full 6 months of treatment that reported feeling complete resolution of symptoms at month 6 visit and had no worsening of condition at the month 9 follow up visit.

Time frame: Months 6 and 9

Population: Patients randomized to combination antibiotics who believed that their disease went into complete remission during the trial

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Azithromycin & RifampinNumber of Patients With a Complete Response (Resolution of All Symptoms)5 Participants
Doxycycline & RifampinNumber of Patients With a Complete Response (Resolution of All Symptoms)1 Participants
PlaceboNumber of Patients With a Complete Response (Resolution of All Symptoms)0 Participants
Secondary

PhGA Assessment

Comparison of Physician's global assessment of disease activity (PhGA) using 0-100mm visual analog scale (VAS) , where 0 indicates the best possible outcome and 100 indicates the worst possible outcome, in combination antibiotic vs placebo groups at Baseline, month 1,3,6 and 9

Time frame: Baseline, month 1,3,6 and 9

ArmMeasureGroupValue (MEAN)
Azithromycin & RifampinPhGA AssessmentMonth 135.2 units on a scale
Azithromycin & RifampinPhGA AssessmentMonth 616.3 units on a scale
Azithromycin & RifampinPhGA AssessmentMonth 323.2 units on a scale
Azithromycin & RifampinPhGA AssessmentMonth 917.7 units on a scale
Azithromycin & RifampinPhGA AssessmentBaseline63.9 units on a scale
Doxycycline & RifampinPhGA AssessmentMonth 943.8 units on a scale
Doxycycline & RifampinPhGA AssessmentBaseline60.2 units on a scale
Doxycycline & RifampinPhGA AssessmentMonth 152.9 units on a scale
Doxycycline & RifampinPhGA AssessmentMonth 349.4 units on a scale
Doxycycline & RifampinPhGA AssessmentMonth 645.7 units on a scale
Secondary

Swollen 76 Joint Count (SJC)

Comparison of modified Swollen Joint Counts between combination antibiotic and placebo groups at Baseline, Month 1, 3, 6 and 9. Determination of swelling in each of the 76 joints was determined by any swelling or absence of swelling. Each swollen joint receives a value of 1, ranging from 0-76 as a possible score.

Time frame: Baseline, month 1,3,6 and 9

ArmMeasureGroupValue (MEAN)
Azithromycin & RifampinSwollen 76 Joint Count (SJC)Month 11.7 Swollen Joints
Azithromycin & RifampinSwollen 76 Joint Count (SJC)Month 30.9 Swollen Joints
Azithromycin & RifampinSwollen 76 Joint Count (SJC)Month 60.9 Swollen Joints
Azithromycin & RifampinSwollen 76 Joint Count (SJC)Month 90.5 Swollen Joints
Azithromycin & RifampinSwollen 76 Joint Count (SJC)Baseline4.1 Swollen Joints
Doxycycline & RifampinSwollen 76 Joint Count (SJC)Month 65.2 Swollen Joints
Doxycycline & RifampinSwollen 76 Joint Count (SJC)Month 13.5 Swollen Joints
Doxycycline & RifampinSwollen 76 Joint Count (SJC)Baseline4.5 Swollen Joints
Doxycycline & RifampinSwollen 76 Joint Count (SJC)Month 34.3 Swollen Joints
Doxycycline & RifampinSwollen 76 Joint Count (SJC)Month 95.1 Swollen Joints

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026