Antibiotics for gastritis: when are they needed and what regimens are used

The term "gastritis" encompasses various conditions of the gastric mucosa with varying causes and prognoses: Helicobacter pylori infection, autoimmune gastritis, chemically reactive changes secondary to bile reflux, drug-induced damage due to nonsteroidal anti-inflammatory drugs, and others. For most of these conditions, antibiotics show no benefit and are sometimes harmful. The exception is Helicobacter pylori infection and rare specific gastric infections, where eradication therapy improves outcomes, including a reduced risk of ulcers and gastric cancer. This is reflected in international consensus guidelines and updates on gastritis. [1]

Current consensus suggests thinking "by cause" rather than "by the word gastritis." For the infectious variant, detection of Helicobacter pylori and targeted eradication are required. For the autoimmune variant, the priorities are different: correction of deficiencies, assessment of cancer risks, and monitoring. The approach of "antibiotics for everyone with epigastric pain" is considered outdated and leads to microbial resistance and unnecessary adverse reactions. [2]

The first diagnostic step in dyspepsia is to confirm or exclude Helicobacter pylori using validated tests. A negative result changes the strategy: the default is to prescribe antisecretory therapy and eliminate risk factors, but antibiotics are not used. This is the basic logic of "test and treat" strategies in primary care. [3]

Bottom line: antibiotics "for gastritis" are not always indicated. They are needed when Helicobacter pylori infection is confirmed or there is a rare, proven bacterial infection. In all other cases, the priorities are different: protecting the mucosa, controlling risk factors, and monitoring the specific gastritis profile. [4]

Table 1. "Gastritis" and the place of antibiotics

Cause	What's happening	Are antibiotics necessary?	Key priorities
Helicobacter pylori	Chronic inflammation of the mucous membrane, risk of ulcers and cancer	Yes, eradication therapy	Correct treatment plan and monitoring
Autoimmune gastritis	Immune damage to parietal cells	No	Vitamin B12, risk assessment, observation
Reactive chemical	Bile reflux, mucosal irritation	No	Reflux correction, mucosal protection
Drug	Nonsteroidal anti-inflammatory drugs and others	No	Cancellation of the causative factor, gastroprotection

Summarized from consensus and clinical updates. [5]

How to Properly Confirm Helicobacter Pylori Infection

In primary care, noninvasive tests are used for patients with uncomplicated dyspepsia: the carbon-13 urea breath test and the fecal antigen test. Rapid serologic tests in the physician's office are not recommended due to their lack of accuracy; laboratory serology is permitted only if its diagnostic value has been locally confirmed. These tests form the basis of the "test and treat" approach. [6]

Before testing, it is important to "wash out" medications that produce false negative results. Proton pump inhibitors should be discontinued for at least 14 days, and bismuth salts and antibiotics should be discontinued for at least 28 days prior to testing. These intervals are crucial and often ignored, reducing infection detection rates. [7]

Endoscopy with biopsy is indicated for "red flags" or a high probability of concomitant pathology: significant weight loss, anemia, dysphagia, vomiting with blood, a hereditary risk of gastric cancer, and age thresholds according to local guidelines. In such patients, Helicobacter pylori testing is combined with mucosal morphology and subsequent follow-up. [8]

If Helicobacter pylori infection is confirmed, the next step is to immediately prescribe the correct regimen and plan treatment monitoring in advance. Delaying eradication or choosing outdated regimens dramatically reduces the chances of success and increases the risk of resistance. [9]

Table 2. Helicobacter pylori tests: how to avoid mistakes

Test	What is important for accuracy	When to apply	Comments
Carbon-13 urease breathalyzer	Discontinuation of proton pump inhibitors for 14 days; antibiotics and bismuth for 28 days	First line of non-invasive diagnostics	High diagnostic value
Fecal antigen	The same "laundering"	An alternative to a breath test	Convenient for monitoring healing
Laboratory serology	Use only validated panels	When other tests are not available	Not suitable for monitoring healing
Endoscopy with biopsy	Red flag indications	In case of risk of oncopathology, complications	Allows for staging gastritis

Recommendations of primary care and specialized societies. [10]

Antibiotics for Helicobacter pylori: What Works

The first-line regimen for most adult patients with no known susceptibility is optimized bismuth quadruple therapy for 14 days. This includes a high-dose proton pump inhibitor, bismuth subsalicylate or subcitrate, metronidazole, and tetracycline. Resistance to clarithromycin and fluoroquinolones is increasing, so the standard clarithromycin-containing triple therapy is not recommended empirically. [11]

Alternatives when bismuth quadruple therapy is not suitable or available include rifabutin as a 14-day triple regimen or dual therapy for 14 days with a potassium-competitive acid pump inhibitor and amoxicillin for patients without penicillin allergy. These options have shown high efficacy and are suitable as rescue regimens after treatment failure. [12]

The clarithromycin triple regimen is only appropriate if Helicobacter pylori susceptibility to clarithromycin is confirmed. Prescribing it "blindly" is associated with low eradication rates and accelerated loss of susceptibility. If susceptibility testing is available, therapy should be based on its results, and if in doubt, a bismuth-containing regimen should be used. [13]

Duration matters: 14-day courses outperform shorter courses in terms of cure rate. High doses of antisecretory agents and adherence to the antibiotic schedule are critical to success, so patients are given detailed instructions in advance on how to avoid missing doses. [14]

Table 3. Recommended empirical regimens for adults in 2025

Scenario	Composition and duration	Who is it suitable for?	Key Notes
Bismuth quadruple therapy 14 days	High-dose proton pump inhibitor, bismuth, metronidazole, tetracycline	First line for unknown sensitivity	Effective in cases of clarithromycin resistance
Rifabutin triple 14 days	Proton pump inhibitor, amoxicillin, rifabutin	Alternative if the first line fails	Convenient for high resistance to macrolides
Potassium-competitive inhibitor plus amoxicillin for 14 days	Potassium-competitive acid pump inhibitor, amoxicillin	An alternative for patients without allergies	High efficiency with good tolerability
Clarithromycin Triple 14 days	Proton pump inhibitor, amoxicillin, clarithromycin	Only with confirmed sensitivity	Do not apply empirically

Summary of recommendations from specialized societies and reviews. [15]

What does "optimized" bismuth quadruple therapy mean?

Optimization involves four components: a sufficient duration of 14 days, an adequate dose of the antisecretory agent, full doses of both antibiotics, and the correct amount of bismuth. An insufficient dose of even one component significantly reduces the chances of cure. This is why guidelines emphasize the term "optimized" regimen. [16]

A proton pump inhibitor is given at a high dose twice daily, which stabilizes gastric pH and enhances antibiotic activity. Bismuth is an important part of the regimen due to its bactericidal and protective properties and helps overcome resistance. Metronidazole and tetracycline are taken strictly as prescribed, without missing doses. [17]

Simple techniques are practically significant: a pre-prepared reminder timer, taking the medication with food as directed to reduce nausea, and proper communication about temporary changes in stool color and darkening of stool associated with bismuth. These are typical "benign" side effects that increase anxiety without explanation and lead to premature discontinuation. [18]

If tolerance limits the dosage, do not "trim" the regimen on your own. The correct approach is to contact your doctor to adjust the treatment, and if severe reactions occur, switch to an alternative regimen without losing the overall 14-day "window of effectiveness." [19]

Table 4. Example of dosages of components of optimized bismuth quadruple therapy in adults

Component	Typical dose and frequency	How to take	Important notes
Proton pump inhibitor high dose	Omeprazole equivalent 20-40 mg twice daily	Before meals	Don't skip your morning dose
Bismuth subcitrate or subsalicylate	According to the instructions for a specific drug, 4 times a day	After meals and at night	Darkening of stool is possible
Metronidazole	500 mg 3-4 times a day	With food	Avoid alcohol
Tetracycline	500 mg 4 times a day	Wash down with water	Do not combine with dairy products

Summarized from current guidelines. Specific trading forms may vary. [20]

Monitoring the cure: when and how

Eradication monitoring is mandatory for all patients. It is performed using a urea breath test or a fecal antigen test no earlier than 28 days after stopping antibiotics and bismuth and after discontinuing the proton pump inhibitor for at least 14 days. This monitoring is part of the treatment, not an "optional" option. [21]

Early testing leads to false negative results and erroneous conclusions that "no infection" is present. Therefore, patients are given a reminder in advance with precise dates for stopping medications and retesting. If the result is positive, a rescue regimen is selected, taking into account previous therapy. [22]

If susceptibility testing is available, it is used to select a rescue regimen. In the absence of such testing, the logic is simple: if bismuth quadruple therapy has not yet been prescribed, it is used; if bismuth has already failed, rifabutin triple therapy or a regimen with a potassium-competitive inhibitor and amoxicillin is used. [23]

For patients with a high oncorisk load or with atrophic changes in the mucosa, the strategy of control and monitoring is expanded: in addition to monitoring the cure, the frequency of endoscopic monitoring is determined according to modern criteria. [24]

Table 5. Preparation for monitoring the cure of Helicobacter pylori

Step	When	What to do
Discontinuation of antibiotics and bismuth	In 28 days	Eliminate residual effect on the test
Proton pump inhibitor discontinuation	In 14 days	Avoid false negative results
Selecting a test	On the day of inspection	Respiratory urease or fecal antigen
Actions based on results	After the test	If positive - rescue scheme

Recommendations of primary care and specialized societies. [25]

Rescue schemes after failure

After the first failure, adherence and drug interactions are assessed first. If bismuth quadruple therapy has not been used previously, it is chosen as the most likely to be successful. If it fails, rifabutin triple therapy or a regimen with a potassium-competitive reuptake inhibitor is switched. The choice depends on drug availability and tolerability profile. [26]

Susceptibility testing increases the chances of success in complex cases and helps avoid unnecessary broad combinations. Molecular methods allow for rapid detection of resistance to clarithromycin and fluoroquinolones and more precise regimen selection. Both approaches again require a 14-day treatment period. [27]

Fluoroquinolone-containing regimens are reserved for later stages and only based on susceptibility testing and safety considerations. Reuse of clarithromycin without susceptibility data is not justified, as the likelihood of resistance increases after failure. [28]

It's important to provide adherence support: step-by-step instructions, follow-up calls, and reminders. These are simple measures that statistically increase cure rates without changing medications. [29]

Table 6. Rescue modes and selection conditions

Previous diagram	What to choose now?	Why	Notes
There was no bismuth quadruple therapy	Bismuth quadruple therapy 14 days	High efficiency with unknown sensitivity	Monitoring of healing is mandatory
There was bismuth quadruple therapy	Rifabutin triple 14 days	Different mechanism, high efficiency	Assess tolerability
Failure on clarithromycin-containing	Bismuth quadruple therapy or rifabutin triple therapy	Clarithromycin resistance is likely	Clarithromycin should not be repeated empirically.
Sensitivity testing is available	Scheme of results	Personalization increases success	Molecular panels speed up selection

Recommendations of specialized societies. [30]

Special groups: pregnancy, children, penicillin allergy

During pregnancy, the treatment goals are the same, but safety is more important than speed. Tetracycline and bismuth-containing salicylates are contraindicated, so classic bismuth quadruple therapy is not used. Preference is given to eradication after childbirth, unless there are urgent indications; if a decision is necessary during pregnancy, protected beta-lactam options are considered with an individual benefit-risk assessment.

In children, regimens and dosages are calculated based on weight, and the feasibility of eradication is assessed based on the indications, including peptic ulcer disease and iron deficiency anemia in cases of proven infection. The principles remain the same: sufficient duration, correct dosages, and mandatory monitoring of cure. [31]

In cases of true penicillin allergy, bismuth quadruple therapy without amoxicillin is the mainstay. If intolerance to any of the components is present, alternative combinations are selected under specialist supervision, taking into account local protocols and susceptibility data. [32]

If, in addition to Helicobacter pylori, a patient is diagnosed with autoimmune gastritis, antibiotics will not resolve the autoimmune problem. Correction of vitamin B12 deficiency, assessment of the risk of neoplasia, and selection of endoscopic monitoring intervals are key. [33]

Table 7. Limitations and precautions

Situation	What to avoid	What to rely on
Pregnancy	Tetracycline, bismuth salicylates	Individual beta-lactam variants or delayed eradication
Children	Adult "fixed" doses	Calculation by mass, cure control
Allergy to penicillins	Amoxicillin	Bismuth quadruple therapy without amoxicillin
Concomitant autoimmune gastritis	Antibiotics for gastritis	Vitamin B12, cancer risk, observation

Summarized from gastroenterological recommendations. [34]

If there is no Helicobacter pylori: what to do with other types of gastritis

In autoimmune gastritis, the key goals are to identify and treat vitamin B12 deficiency, assess the risk of carcinoid tumors and adenocarcinoma, and schedule endoscopic follow-up at intervals based on the stage of atrophy and metaplasia. Antibiotics are not indicated. [35]

In chemically reactive and drug-induced cases, the focus shifts to eliminating the causative factor, protecting the mucosa, and managing bile reflux. Helicobacter pylori eradication is not required with negative tests and only increases the risk of adverse events. [36]

After recovery from Helicobacter pylori infection, some patients remain with atrophic changes. Risk and monitoring recommendations for these patients differ from those for active infection. A properly planned treatment plan reduces the likelihood of late diagnosis of neoplasia. [37]

Thus, the absence of Helicobacter pylori is a signal to switch attention from antibiotics to the causes that actually support the inflammation of the mucosa, and to the prevention of complications. [38]

Table 8. "Gastritis without Helicobacter pylori": where to focus your efforts

Option	Main steps	What to control
Autoimmune	Vitamin B12, gastrin, endoscopic observation	Risks of neoplasia, anemia
Reactive chemical	Reflux therapy, mucosal protection	Symptoms of dyspepsia
Drug	Review of pain relief, gastroprotection	Recurrence of injuries
Vague dyspepsia	Antisecretory therapy, risk factor modification	Dynamics of symptoms

Summarized from clinical documents and consensus. [39]

Common mistakes: how to avoid harm

Mistake #1 is prescribing a clarithromycin triple regimen "out of habit." Without confirmed susceptibility, this leads to eradication failure and increased resistance. Optimized bismuth quadruple therapy for 14 days remains the standard if susceptibility is unknown. [40]

Mistake #2: Not performing a cure check. Without a documented negative test 28 days after therapy and "washouts," treatment cannot be considered complete. This leads to "chronic undertreatment" and repeat visits. [41]

Mistake #3: Giving antibiotics for any type of gastritis. They're useless and risky for autoimmune and reactive gastritis. Completely different interventions and risk-based monitoring are needed. [42]

Mistake #4: Reducing the duration and dosage due to mild side effects. This reduces the likelihood of a cure. The correct strategy is to manage side effects and, if necessary, switch to an alternative, full-strength regimen. [43]

Table 9. Red flags and when to refer for endoscopy

Sign	Why is it important?	Actions
Weight loss, anemia, progressive dysphagia, hematemesis	Risk of hidden serious pathology	Urgent endoscopy and advanced diagnostics
Familial risk of gastric cancer, pronounced atrophic changes	High cancer risk	Monitoring plan according to current recommendations
Age limits according to local protocols	There is a higher probability of serious pathology	Endoscopy as a priority
Repeated eradication failures	Suspicion of stability	Sensitivity testing, rescue schemes

Based on guidelines for dyspepsia and gastritis. [44]

A short algorithm for a practicing physician

Step 1. Confirm or exclude Helicobacter pylori using a validated test with the correct "washes." If the result is positive, begin eradication; if negative, treat the cause of gastritis without antibiotics. [45]

Step 2. If sensitivity is unknown, start with optimized bismuth quadruple therapy for 14 days. Discuss alternatives if bismuth is not suitable or available. Provide clear instructions for use and adherence. [46]

Step 3. Conduct a cure check no earlier than 28 days after antibiotics and 14 days after discontinuing the proton pump inhibitor. If unsuccessful, implement a rescue regimen according to the described rules, with priority given to personalization if susceptibility testing is available. [47]

Step 4. For autoimmune and other non-infectious variants, correct deficiencies, assess cancer risks, and prescribe observation. Antibiotics are not used. [48]