Assessment Of Incidence & Pattern of Drug Induced Gastrointestinal Disorder in a Tertiary Care Teaching Hospital

Adverse Drug Reactions (ADRs) are defined as any harmful, unintended, and undesirable effects of a drug that occur at normal doses used for prevention, diagnosis, or treatment. Gastrointestinal (GI) ADRs are among the most common and can significantly affect patient health and treatment outcomes. Examples include antibiotic-induced constipation and diarrhea, NSAID-induced peptic ulcers, GI bleeding, and drug-induced hepatotoxicity.1,2,3 GI diseases affect the digestive tract, including the mouth, esophagus, stomach, intestines, liver, gallbladder, and pancreas. Drug-induced GI disorders may resemble conditions like irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD), making diagnosis challenging. These disorders may result from altered GI physiology (e.g., constipation from anticholinergics), direct tissue damage (e.g., ulcers from NSAIDs), disruption of gut microbiota (e.g., C. difficile infection from antibiotics), or unknown mechanisms such as those seen with metformin. 4,5 Antibiotic-Associated Diarrhea (AAD) is a common side effect of antibiotic use, occurring during or up to two months after treatment. It ranges from mild diarrhea to severe GI symptoms like abdominal pain, constipation, and flatulence. AAD results from the imbalance of gut bacteria, and nearly all antibiotics can potentially cause it.6 Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are widely used for pain and inflammation but are major contributors to GI toxicity. Most non-H. pylori peptic ulcers are caused by NSAIDs due to the inhibition of protective prostaglandin synthesis. Symptoms include abdominal pain, nausea, vomiting, bloating, and loss of appetite. Severe complications can lead to anaemia, bleeding, or perforation. To reduce risks, NSAIDs should be used cautiously, especially in elderly patients. When necessary, co-administration with proton pump inhibitors (PPIs) or misoprostol is recommended to protect the GI lining. 7,8,9,10 Pharmaceutical preparations are a major cause of liver injury, with hepatotoxicity being the leading cause of acute liver failure. The liver, as the primary organ for drug metabolism and elimination, is vulnerable to damage from various drugs such as anti-tubercular agents, anesthetics, paracetamol, anti-cancer drugs, steroids, vaccines, and antivirals—especially with long- term use. Hepatotoxic reactions may be predictable (dose-related and occurring shortly after exposure) or unpredictable (not dose-related and with delayed onset). It is essential to assess patients thoroughly before prescribing hepatotoxic drugs, monitor liver enzymes regularly, use the lowest effective doses, and educate patients to report symptoms early for timely intervention. 11,12 The review of literature presents various studies addressing upper gastrointestinal complications related to NSAID use, highlighting prevalence, risk factors, and associated patient outcomes. It summarizes research that investigates the incidence of bleeding, ulceration, and drug-related GI events in different populations, often comparing NSAID use to control groups or other therapies. Other studies focus on comorbid conditions, diagnostic patterns, prognostic markers, and management strategies, revealing consistently higher GI risk in patients exposed to NSAIDs and related medications, especially in those with comorbid illnesses or predisposing factors. Taken together, these findings emphasize the clinical importance of monitoring and mitigating gastrointestinal risks in patients receiving NSAID therapy across diverse patient populations.

Pharmacists play a vital role in managing and preventing drug- induced gastrointestinal (GI) disorders. They can reduce antibiotic-associated GI issues and NSAID- induced ulcers through patient counseling, medication reviews, recommending probiotics or gastroprotective agents, and providing dietary advice. By collaborating with healthcare providers, they help ensure safer medication choices and promote adherence to monitoring protocols. So this study was conducted to analyze the frequency, patterns, and real- world impact of GI adverse drug reactions. The findings will support better prescribing practices, improve pharmacovigilance, and enhance patient safety in order to enhance and develop the Sustainable Development Goals (SDGs) of Govt. of India.

MATERIALS ANE METHODS: 8

A prospective observational study was conducted at Department of Gastroenterology, Navodaya Medical College Hospital and Research Center, which is a tertiary care teaching hospital over a duration of three months and included a sample size of 150 patients. Patients eligible for inclusion were those admitted to the hospital during the study period and receiving antibiotic treatment, NSAIDs, or other medications known to cause gastrointestinal (GI) side effects. Additionally, only patients with a confirmed diagnosis of drug-induced gastrointestinal disease, supported by medical records, were considered. Exclusion criteria comprised patients not admitted to the hospital, those with pre-existing gastrointestinal diseases that could confound the assessment of drug-induced effects, individuals unable to provide accurate information about their symptoms or medication history, and patients with incomplete medical records that would hinder establishing a clear link between drug exposure and GI disease. Furthermore, patients with severe co-morbidities that could independently affect gastrointestinal health (such as advanced cancer, or severe liver or kidney disease), as well as pregnant or breastfeeding women, were excluded from the study. The study was approved Institutional Ethical Committee of study hospital by using ethical clearance certificate.

Sample Size Calculation⁹:

P= 0.096, Z= 3.8416 at 95% CI, d= 0.000025

n=z2 x p(1-p)/d2 So, n= 133.2= 150

The project team visited the study ward on a routine basis, recorded the cases, monitored for possible adverse drug reactions (ADRs), and interacted with patients to determine if they experienced any gastrointestinal (GI) side effects after the administration of the suspected drugs.GI ADRs were obtained, were assessed for causality by using Naranjo Scale and confirmed it through AMC of study hospital. The collected information was compiled in MS Excel and analyzed using descriptive statistics to determine the incidence & pattern of drug induced gastrointestinal disorder.

Statistical Analysis:

The data collected was consolidated in an MS Excel spread sheet (2007 version). The data was meticulously checked for completeness and accuracy. Descriptive statistics, including frequencies and percentages were used to analyze the data.

RESULTS

"Assessment   of         Incidence        and Pattern of Drug-Induced Gastrointestinal Disorders in a Tertiary Care Teaching Hospital" was conducted on 150 patients at Navodaya Medical College Hospital and Research Centre, Raichur.

DEMOGRAPHIC DETAILS OF PATIENTS

The study population was predominantly aged 18–60 years (80%), with the highest proportions in the 18– 30 (23%) and 31–40 (22%) age groups; the mean age was 45 with the standard deviation of 14.37. Unlike many ADR studies focusing on older adults, this younger demographic may still face risks due to lifestyle factors and drug exposure. Females comprised 55% of participants, aligning with other studies where women show higher ADR incidence, possibly due to hormonal, metabolic differences, and higher medication use for GI conditions like GERD and Irritable Bowel Syndrome. Data were shown in Table No 1 & Fig No 1. The male to female ratio was 9:11.

Fig.1: Gender Distribution (n=150)

Table 1: Age Distribution of Study Participants (n=150)

As shown in Table No. 2 we found that 69% of patients were non-users of tobacco or alcohol, while 11% were smokers, and 7% consumed alcohol. It was important to noted that smoking and alcohol use were known to exacerbate the risk of drug-induced gastrointestinal disorders, especially when combined with medications like NSAIDs and corticosteroids, which already predispose individuals to ulcers and GI bleeding.

Table 2: Social History of Study Participants (n=150)

We observed that several laboratory investigations were performed on patients with hemoglobin levels and white blood cell counts being the most common tests performed (Table 3). These investigations reflect the need to monitor drug effects on systemic health, especially when GI disorders can result in complications like anemia. Other diagnostic procedures included ultrasound scans (17%), smear tests (20%), and other imaging techniques , which help in diagnosing the severity and possible secondary effects of GI ADRs.Data was Shown in Fig. 2

Table 3: Laboratory Investigations Performed on Study Participants(n=400)

* Include MCH, HIV, Platelet, RDW-CV, TSH, RBC.

Fig 2: Other Investigations Performed on Study Participants (n=150)

The reasons for hospital admissions showed a diverse range of diagnoses, with ovarian cystic disorders (17%) and hypothyroidism (17%) being prominent (Fig. 3). Although these conditions are not directly linked to GI disorders, the medications used, such as NSAIDs or thyroid medications, can contribute to ADRs. The need for early monitoring and preventive care in high-risk patients was evident.

Fig 3: Reason for Admission of Study Participants (n=150)

Majority of ADRs were identified during ward rounds (75%) (Table 4). This reflects the importance of regular patient monitoring in detecting and addressing ADRs promptly.

Table 4: ADR Identification Methods (n=20)

Incidence of drug induced G.I disorders was calculated using the appropriate formula and found as 0.5333 Cases/Patient-Years. The Incidence value or Incidence rate is a measure of how often an event occurs over a specific period of time. An Incidence rate that is less than one percent means that the risk of an ADR (Drug induced G.I Disorders) in a study population is decreased.

Incidence of Drug Induced G.I Disorder

Among the 20 documented gastrointestinal (G.I.) adverse drug reactions (ADRs), nausea and vomiting were most common, affecting 75% of patients, particularly those on antibiotics, chemotherapy, and NSAIDs. Peptic ulcer disease (PUD) occurred in 10% of participants, mainly linked to NSAID use, which impairs gastric mucosal protection. Diarrhea, also reported in 10% of cases, was largely associated with antibiotics—especially penicillin (35%), fluoroquinolones (25%), and nitroimidazoles (15%). These findings highlight the need for careful monitoring of high-risk drugs to ensure better patient safety and adherence which was depicted at Table No. 5

Table 5: Types of Drug-Induced GI Disorders Observed (n=20)

As Shown in Fig. 4 the most commonly implicated drug classes for ADRs included penicillin antibiotics (25%) and fluoroquinolones (25%), followed by nitroimidazoles (15%) and NSAIDs (10%) . These medications are well-documented for their GI side effects, including nausea, ulcers, and diarrhea. Co-prescription of gastroprotective agents, such as proton pump inhibitors, could have mitigated the risks.

Fig 4: Drugs Most Commonly Associated with GI Disorders (n=20)