NAC in Spontaneous Bacterial Peritonitis

August 31, 2026 updated by: Khadija Ahmed Mhrose Glal, Tanta University

Adjunctive N-Acetylcysteine in the Management of Spontaneous Bacterial Peritonitis in Patients With Liver Cirrhosis: A Randomized Controlled Trial

Spontaneous bacterial peritonitis (SBP) is one of the most serious infectious complications of liver cirrhosis and ascites. It affects approximately 10-30% of hospitalized patients with decompensated cirrhosis and carries an in-hospital mortality of 20-40% despite appropriate antimicrobial therapy (1,2). SBP results from bacterial translocation across the intestinal mucosa together with cirrhosis-associated immune dysfunction, leading to impaired bacterial clearance and exaggerated systemic inflammation (3). Current international guidelines recommend immediate empirical antibiotic therapy together with intravenous human albumin to reduce the incidence of acute kidney injury (AKI), hepatorenal syndrome, and mortality (2,4).

Although this strategy has substantially improved outcomes, treatment failure, persistent infection, renal dysfunction, acute-on-chronic liver failure (ACLF), and early mortality remain common, indicating that currently available therapy does not adequately address all pathogenic mechanisms of SBP (2,4). Increasing evidence suggests that oxidative stress is a central contributor to the progression of bacterial infections in cirrhosis. Excessive production of reactive oxygen species aggravates hepatocellular injury, endothelial dysfunction, immune dysregulation, and renal impairment, thereby amplifying systemic inflammatory responses during SBP (5,6). Consequently, therapeutic strategies targeting oxidative stress may improve host defense while limiting organ injury.

N-acetylcysteine (NAC) is a precursor of glutathione and one of the most extensively studied antioxidant agents in clinical medicine. Besides restoring intracellular glutathione stores, NAC exerts anti-inflammatory, endothelial-protective, and immunomodulatory effects through inhibition of oxidative stress and pro-inflammatory cytokine production (5,7). On the other hand, experimental studies have further demonstrated that NAC can inhibit bacterial biofilm formation, enhance antibiotic penetration, and potentiate antimicrobial activity against several clinically important bacterial pathogens (8,9).

Despite these promising biological properties, the therapeutic role of NAC in active SBP has not been established. Previous data have primarily evaluated NAC for hepato- or renal protection in liver disease (10). While its potential role as an adjunctive antibacterial therapy during active SBP has not been investigated in adequately designed randomized controlled trials. Therefore, the present study will evaluate whether adjunctive NAC improves early treatment response and reduces subsequent organ dysfunction and short-term adverse outcomes.

Study Overview

Status

Not yet recruiting

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 2
  • Phase 1

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria: Adult patients (≥18 years) with liver cirrhosis, confirmed by clinical, radiological, or histopathological findings, who are newly diagnosed with SBP based on an ascitic fluid polymorphonuclear (PMN) leukocyte count ≥250 cells/mm³ according to the American Association for the Study of Liver Diseases (AASLD) criteria (2). Eligible participants were required to have undergone diagnostic paracentesis for ascitic fluid analysis and to provide informed consent prior to enrollment.

Exclusion Criteria

  • Secondary bacterial or fungal peritonitis.
  • Recent abdominal surgery or requiring immediate surgical intervention.
  • Known hypersensitivity to NAC.
  • Pregnancy or lactation.
  • Septic shock, established HRS-AKI requiring rescue therapy, or renal replacement therapy at enrollment.
  • Advanced malignancy or terminal illness.
  • Previous NAC administration during the current SBP episode.
  • Inability to receive oral study medication.
  • Participation in another interventional trial that may affect study outcomes.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: CONTROL
Standard-of-care SBP therapy + matching placebo twice daily for 7 days.
Active Comparator: NAC
Standard-of-care SBP therapy + NAC 600 mg orally twice daily for 7 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage change in ascitic-fluid polymorphonuclear (PMN) count from baseline to 48 hours after initiation of treatment
Time Frame: 48 H

Primary Outcome: Percentage change in ascitic-fluid polymorphonuclear (PMN) count from baseline to 48 hours after initiation of treatment.

% change = [(48-h PMN - baseline PMN) / baseline PMN] × 100

48 H

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 10, 2026

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

August 31, 2026

First Submitted That Met QC Criteria

August 31, 2026

First Posted (Actual)

September 4, 2026

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

August 31, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • NAC&SBP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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