A Phase 4 interventional study of Amoxicillin and Placebo in Autoimmune Rheumatic Diseases, Tooth Extraction and Infection Prevention, sponsored by University of Sao Paulo General Hospital. Recruiting at 1 site in Brazil. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-15.
Sponsored by University of Sao Paulo General Hospital · Phase 4, Interventional, and Prevention
This randomized, double-blind, placebo-controlled clinical trial aims to evaluate whether single-dose amoxicillin prophylaxis administered prior to simple tooth extraction reduces postoperative infection rates inpatients with autoimmune rheumatic diseases (ARDs).
Although antibiotic prophylaxis is not recommended for healthy individuals undergoing simple extractions, immunosuppressed ARD patients frequently receive antibiotics despite limited evidence supporting this practice.
Secondary objectives include assessing infection severity, postoperative complications, and the impact of ARD diagnosis and immunosuppressive treatment on infection risk.
Simple tooth extractions are common procedures, and postoperative infection rates are low in the general population. Current guidelines discourage prophylactic antibiotic use to reduce microbial resistance, adverse reactions, and microbiome disruption.
However, patients with ARDs often receive prophylaxis due to theoretical risks of delayed healing and increased susceptibility to infection. Evidence in other immuno-compromised populations suggests that simple extractions may be safe without antibiotics, but no prospective trials have evaluated this issue specifically in ARD patients.
This study is the first prospective, randomized, double-blind, placebo-controlled trial designed to determine whether antibiotic prophylaxis is necessary in this population.
264 studies on the registry are indexed under Rheumatic Diseases; 60 are open to participants now.
This study's planned enrollment of 352 is above the median of 100 across 167 interventional studies indexed under Rheumatic Diseases.
Browse Rheumatic Diseases studies →University of Sao Paulo General Hospital is the lead sponsor of 611 studies on the registry; 98 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 0 (0%) 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 weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Four amoxicilin tablets (2g total) administered as single dose 30-60 minutes before tooth extraction
Drug: Amoxicillin
Four matching placebo tablets administered 30-60 minutes before tooth extraction
Other: Placebo
Amoxicillin 2 g a single prophylactic dose prior to simple extraction.
Matching placebo tablets administered as a single dose prior to extraction
Frequency of postoperative infections
Proportion of participants developing postoperative infection, defined as purulent/serous exudate, fever, or clinical signs of local infection.
Time frame: 7 days post-extraction
Incidence of Postoperative Complications
Presence of alveolitis, fever, edema, erythema, trismus, exudate, and pain between the two groups
Time frame: 7 days post-extraction
Severity and Duration of Infection
To compare the duration and severity of the infection and any possible differences between the two groups
Time frame: 7 days post-extraction
impact of demographic data, different ARDs; disease activity, and treatment
Compare the potential impact of demographic data, different ARDs; and treatment on the frequency and severity of infection in the two groups;
Time frame: 7 days post-extraction
Oral Health in the different ARDs
Characterize oral health in the different ARDs using the decayed, missing, or filled teeth index (DMF) and the simplified periodontal screening and recording (PSR).
Time frame: Day 1
Plan to share: No
Started Oct 2026 (actual). Primary completion is estimated for Jun 2029, 31 months after the start.
Start moved once since we started tracking on Sep 25, 2026: Aug 2026 → Oct 2026, on Oct 15, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Amoxicillin
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