Non-communicable diseases (NCDs) are responsible for approximately 71% of global deaths and represent a major public health challenge worldwide. Chronic conditions such as diabetes mellitus, hypertension, cardiovascular diseases, chronic kidney disease, and chronic obstructive pulmonary disease often require long-term pharmacotherapy involving multiple medications. Polypharmacy is commonly defined as the concurrent use of five or more medications. Although polypharmacy may be clinically appropriate in managing multiple comorbidities, excessive medication use increases the risk of adverse drug reactions (ADRs), drug-drug interactions (DDIs), medication errors, non-adherence, functional decline, and hospitalization. Pharmacovigilance encompasses the detection, assessment, understanding, and prevention of adverse effects or any drug-related problems. In patients with chronic diseases, effective pharmacovigilance systems are essential to monitor medication safety and optimize therapeutic outcomes. The increasing prevalence of multimorbidity and aging populations has intensified concerns regarding inappropriate polypharmacy. Previous studies have highlighted associations between polypharmacy and adverse clinical outcomes; however, prospective evidence from routine clinical settings remains limited. Therefore, the present study aimed to evaluate pharmacovigilance indicators and clinical outcomes associated with polypharmacy among patients with chronic NCDs.

Study Design A hospital-based prospective observational study was conducted over a period of twelve months. Study Setting The study was carried out in the outpatient and inpatient departments of a tertiary care teaching hospital. Study Population Adult patients diagnosed with one or more chronic non-communicable diseases and receiving long-term pharmacotherapy were screened for eligibility. Inclusion Criteria • Age ≥18 years. • Diagnosed with chronic NCDs for at least six months. • Receiving five or more prescribed medications. • Willing to provide informed consent. Exclusion Criteria • Pregnant and lactating women. • Patients with acute medical emergencies. • Individuals unable to provide reliable clinical information. • Terminally ill patients. Sample Size A total of 320 eligible patients were included using convenience sampling. Data Collection A structured case record form was used to collect: • Demographic information. • Clinical diagnosis and comorbidities. • Medication history. • Number of prescribed drugs. • ADR reports. • Drug interaction profiles. • Hospitalization records. • Medication adherence status. Pharmacovigilance Assessment ADR causality assessment was performed using the WHO-UMC scale and categorized as: • Certain • Probable • Possible • Unlikely Drug-drug interactions were identified using standard interaction databases. Outcome Measures Primary Outcomes: • Frequency of ADRs. • Prevalence of DDIs. Secondary Outcomes: • Hospitalizations. • Emergency visits. • Medication adherence. • Disease control status. Statistical Analysis Data were analyzed using SPSS version 25. Continuous variables were expressed as mean ± standard deviation, while categorical variables were expressed as frequencies and percentages. Chi-square test and logistic regression analysis were used to determine associations. A p-value <0.05 was considered statistically significant.

Baseline Characteristics Among 320 participants, 182 (56.9%) were males and 138 (43.1%) were females. The mean age was 58.4 ± 11.2 years. Table 1. Demographic Characteristics of Participants Variable Frequency (%) Male 182 (56.9) Female 138 (43.1) Age 18–40 years 42 (13.1) Age 41–60 years 146 (45.6) Age >60 years 132 (41.3) Table 2. Distribution of Chronic Diseases Disease Frequency (%) Hypertension 232 (72.5) Diabetes Mellitus 207 (64.7) Cardiovascular Disease 102 (31.9) Chronic Kidney Disease 54 (16.9) COPD 47 (14.7) Table 3. Polypharmacy Profile Category Frequency (%) 5–9 Drugs 174 (54.4) ≥10 Drugs 45 (14.0) The mean number of prescribed medications was 7.8 ± 2.4. Overall prevalence of polypharmacy was 68.4%. Table 4 Adverse Drug Reactions ADR Frequency (%) Gastrointestinal Disturbances 27 (28.1) Dizziness 19 (19.8) Hypoglycemia 14 (14.6) Electrolyte Imbalance 11 (11.5) Skin Reactions 9 (9.4) Others 16 (16.6) A total of 96 ADRs were identified in 78 patients. Table 5 Causality Assessment Category Number (%) Certain 11 (11.5) Probable 34 (35.4) Possible 43 (44.8) Unlikely 8 (8.3) Table6 Drug-Drug Interactions Severity Frequency (%) Major 21 (15.3) Moderate 82 (59.9) Minor 34 (24.8) Clinical Outcomes Patients receiving ≥10 medications had: • Higher hospitalization rates (24.4% vs 11.5%). • Greater incidence of ADRs (38.7% vs 19.2%). • Lower medication adherence (61.3% vs 81.7%). These differences were statistically significant (p < 0.05).

The present study demonstrated a high prevalence of polypharmacy among patients with chronic NCDs. Hypertension and diabetes were the leading contributors to multiple medication use, reflecting global disease trends. The prevalence of ADRs observed in this study is consistent with previous reports indicating increased medication-related harm among patients receiving multiple therapies. Gastrointestinal disturbances and dizziness were the most frequently reported ADRs, likely due to antihypertensive, antidiabetic, and cardiovascular medications. Drug-drug interactions were identified in nearly half of all prescriptions, emphasizing the need for routine medication review. Patients exposed to excessive polypharmacy experienced significantly poorer clinical outcomes, including increased hospitalization and reduced adherence. These findings reinforce the importance of pharmacovigilance activities within routine clinical practice. Active ADR monitoring, medication reconciliation, and pharmacist-led interventions can substantially reduce preventable medication-related complications. Limitations • Single-center study. • Moderate sample size. • Potential underreporting of ADRs. • Follow-up period limited to six months.

Polypharmacy remains highly prevalent among patients with chronic non-communicable diseases and contributes significantly to adverse drug reactions, drug interactions, hospitalization, and poor medication adherence. Strengthening pharmacovigilance systems and implementing regular medication review programs may enhance patient safety and optimize clinical outcomes

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