Drug Utilization Patterns, Polypharmacy, And Adverse Drug Reactions Among Patients Attending A Tertiary Care Cardiac Emergency: A Prospective Observational Study

Cardiovascular diseases remain a major cause of morbidity and mortality worldwide and represent an important burden on healthcare systems.¹ Cardiac emergency departments manage patients with acute and potentially life-threatening conditions requiring rapid diagnosis, stabilization, and pharmacological intervention. Common presentations include acute myocardial infarction, acute coronary syndrome, hypertensive emergencies, acute pulmonary edema, acute heart failure, cardiogenic shock, life-threatening arrhythmias, pulmonary embolism, and other critical cardiovascular conditions. The complexity and severity of these conditions frequently necessitate the use of multiple medications simultaneously to achieve rapid clinical stabilization and prevent further complications.²

Drug utilization evaluation is an important component of rational pharmacotherapy and provides information regarding prescribing patterns, commonly used therapeutic classes, and medication burden in a specific patient population.³ Evaluation of drug utilization patterns can help characterize medicine use and identify opportunities for improving rational and safe pharmacotherapy.³

Polypharmacy is frequently encountered among patients with cardiovascular disease because acute cardiovascular conditions may coexist with multiple chronic diseases and risk factors. Although multiple medications may be clinically justified, increasing medication burden can increase the potential for medication-related problems and adverse outcomes.??? Older patients may be particularly vulnerable because of multimorbidity and age-related changes that can affect medication response.?

ADRs represent an important medication-related problem in hospitalized and acute-care populations. Systematic reviews have demonstrated that ADRs are common among hospitalized patients and may contribute to morbidity and healthcare utilization.??? Pharmacovigilance therefore remains an important component of medication safety, particularly where multiple medicines and high-risk therapies are used.?

Previous studies have evaluated ADRs and polypharmacy in hospitalized populations, but an integrated assessment of drug utilization, polypharmacy, and ADR occurrence in a tertiary-care cardiac emergency remains useful for identifying patients who may require closer medication monitoring. The present study therefore evaluated these factors and examined their relationships with selected demographic and clinical characteristics.

AIM

To evaluate drug utilization patterns, polypharmacy, and adverse drug reactions among patients attending a tertiary care cardiac emergency.

OBJECTIVES

To assess the demographic and clinical characteristics of patients attending the cardiac emergency.

To evaluate the pattern of drug utilization, including commonly used therapeutic categories and individual drugs.

To determine the prevalence of polypharmacy among the study population.

To identify and assess the occurrence and severity of adverse drug reactions.

To evaluate the association between polypharmacy and adverse drug reaction occurrence.

To assess the association of selected demographic and clinical factors with polypharmacy and adverse drug reactions.

MATERIALS AND METHODS

STUDY DESIGN AND SETTING

A prospective observational study was conducted in the Cardiac Emergency Department of a tertiary care institute. The study was initiated after obtaining approval from the Institutional Review Board and Institutional Ethics Committee. Patient cases were identified and documented by the investigators from the participating hospital.

STUDY DURATION AND STUDY POPULATION

The study was conducted over a period of six months. All patients attending the cardiac emergency department during the study period were considered for evaluation. A total of 700 patient prescriptions and available medical records were reviewed. Relevant demographic, clinical, and medication-related information was systematically collected.

INCLUSION CRITERIA

Patients were included if they attended the cardiac emergency department during the study period, had a documented cardiac or cardiovascular clinical condition, had a prescription or medical record available for evaluation, and had sufficient demographic and medication-related information for assessment.

EXCLUSION CRITERIA

Patients were excluded if their prescriptions or medical records were incomplete or contained insufficient information for evaluation. Duplicate records or records without adequate medication-related information were also excluded.

DATA COLLECTION

Data were collected from patient prescriptions and available medical records using a structured data-collection format. Demographic characteristics, presenting cardiac condition, documented comorbidities, prescribed medications, family history of coronary artery disease, number and type of medications, polypharmacy status, and occurrence and severity of ADRs were recorded.

ASSESSMENT OF DRUG UTILIZATION

Drug utilization was evaluated by recording the individual medications prescribed to the study population and categorizing them according to their major therapeutic classes. The total number of drug entries, average number of drugs per evaluated encounter, commonly utilized individual drugs, essential medicines, generic prescriptions, fixed-dose combinations, and injectable preparations were evaluated.

ASSESSMENT OF POLYPHARMACY

Patients were classified according to their recorded polypharmacy status.

ASSESSMENT OF ADVERSE DRUG REACTIONS

ETHICAL CONSIDERATIONS

The study received ethical clearance from the Institutional Human Ethics Committee of Nargund College of Pharmacy, Bengaluru (Ref. No. NCP/IHEC/-CERTI-025/2025; dated 17/07/2025; committee meeting held on 15/07/2025). The study was conducted in accordance with the permission granted by the Institutional Human Ethics Committee. For Toufik Sarkar, who was affiliated with a different institution during case-data collection, relevant institutional permission from his college was obtained for collection of case data. Patient information was handled confidentially and used only for research purposes.

STATISTICAL ANALYSIS

The collected data were entered, organized, and analyzed using IBM SPSS Statistics version 32.0. Categorical variables were expressed as frequencies and percentages. Associations between categorical variables were evaluated using the Pearson chi-square test. For appropriate 2 × 2 comparisons, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The associations evaluated included age with polypharmacy, sex with polypharmacy, clinical condition with polypharmacy, polypharmacy with ADR occurrence, polypharmacy with ADR severity, age with ADR occurrence, and sex with ADR occurrence. A p-value <0.05 was considered statistically significant.

RESULTS

DEMOGRAPHIC CHARACTERISTICS

A total of 700 patients attending the tertiary care cardiac emergency were evaluated. Among them, 490 (70.0%) were male and 210 (30.0%) were female. The largest proportion belonged to the 40–59-year age group (398; 56.86%), followed by 60–79 years (163; 23.29%), 0–39 years (80; 11.43%), and ≥80 years (59; 8.43%).

TABLE 1. DEMOGRAPHIC CHARACTERISTICS OF THE STUDY POPULATION

COMORBIDITIES

The recorded comorbidities included diabetes mellitus (262), hypertension (186), hypothyroidism (52), diabetes mellitus with hypertension (112), hypertension with hyperthyroidism (9), dyslipidemia (52), and hypertension with hypothyroidism (27). These categories were not mutually exclusive because individual patients could have more than one documented comorbidity.

FAMILY HISTORY

A positive family history of coronary artery disease was documented in 56% of patients, whereas 44% had no documented family history.

CLINICAL CONDITIONS

Acute myocardial infarction was the most frequently recorded clinical condition, accounting for 456 patients (65.14%), followed by unstable angina/acute coronary syndrome (63; 9.00%) and hypertensive emergency (50; 7.14%). Acute severe heart failure accounted for 36 patients (5.14%), while acute pulmonary edema accounted for 30 (4.29%).

TABLE 2. DISTRIBUTION OF CLINICAL CONDITIONS AND POLYPHARMACY STATUS

POLYPHARMACY

Polypharmacy was identified in 294 of 700 patients (42.0%), whereas 406 patients (58.0%) were classified as having no polypharmacy.

TABLE 3. DISTRIBUTION OF POLYPHARMACY AMONG STUDY PARTICIPANTS

DRUG-COUNT DISTRIBUTION

A total of 3,453 individual drug entries were recorded across 700 evaluated prescriptions/patient encounters, corresponding to an average of 4.93 recorded drug entries per evaluated encounter. Among the recorded drug entries, 1,504 (43.56%) were in the 0–4 drug-entry category, 1,894 (54.84%) in the 5–8 category, and 55 (1.59%) in the 9–12 category. These values represent individual drug entries and should not be interpreted as the number of patients or prescriptions in each category.

TABLE 4. DISTRIBUTION OF RECORDED DRUG ENTRIES

MAJOR DRUG CATEGORIES

Antiplatelets were the most frequently recorded major drug category, accounting for 730 entries (21.14%), followed by cardiovascular drugs (680; 19.69%), other drugs (558; 16.16%), anticoagulants (450; 13.03%), and diuretics (360; 10.43%).

TABLE 5. DISTRIBUTION OF MAJOR DRUG CATEGORIES

TOP 10 MOST FREQUENTLY RECORDED INDIVIDUAL DRUGS

Aspirin was the most frequently recorded individual drug, with 350 entries (10.14%), followed by clopidogrel (250; 7.24%), atorvastatin (190; 5.50%), enoxaparin (180; 5.21%), and metoprolol (170; 4.92%).

TABLE 6. TOP 10 MOST FREQUENTLY RECORDED INDIVIDUAL DRUGS

INDIVIDUAL DRUG DISTRIBUTION

The detailed distribution demonstrated the use of multiple agents across antiplatelet, anticoagulant, hypolipidemic, cardiovascular, gastrointestinal, diuretic, antibiotic, opioid, NSAID, and other emergency-drug categories. Within the antiplatelet category, aspirin (350; 10.14%) and clopidogrel (250; 7.24%) were most frequently recorded. Among anticoagulants, enoxaparin (180; 5.21%) and unfractionated heparin (140; 4.05%) were most frequently recorded. Atorvastatin was the most frequently recorded hypolipidemic (190; 5.50%), while furosemide was the most frequently recorded diuretic (220; 6.37%).

MEDICATION-USE INDICATORS

Of the 3,453 recorded drug entries, 2,785 (80.65%) were from the Essential Medicines List, 152 (4.40%) were prescribed by generic name, 443 (12.83%) were fixed-dose combinations, and 456 (13.21%) were injectable medicines. These indicators were not mutually exclusive and therefore were not expected to sum to 100%.

TABLE 7. MEDICATION-USE INDICATORS

ADVERSE DRUG REACTIONS

A total of 149 ADR events/episodes were recorded. Of these, 85 (57.05%) were mild, 48 (32.21%) were moderate, and 16 (10.74%) were severe.

TABLE 8. DISTRIBUTION OF ADVERSE DRUG REACTIONS ACCORDING TO SEVERITY

FREQUENTLY REPORTED ADVERSE DRUG REACTIONS

Headache was the most frequently reported ADR (12; 8.05%), followed by nausea and hypotension (10 each; 6.71%), dizziness (9; 6.04%), constipation and diarrhea (8 each; 5.37%), and vomiting, fatigue, and bradycardia (7 each; 4.70%). Gastric irritation and hypokalemia were each reported in 6 cases (4.03%).

TABLE 9. MOST FREQUENTLY REPORTED ADVERSE DRUG REACTIONS

INFERENTIAL STATISTICAL ANALYSIS

Pearson chi-square analysis demonstrated a statistically significant association between age group and polypharmacy (χ²=31.507, df=3, p<0.001). The proportion of polypharmacy was 25.0% in patients aged 0–39 years, 37.7% in those aged 40–59 years, 58.3% in those aged 60–79 years, and 49.2% among patients aged ≥80 years. A statistically significant association was also observed between clinical condition and polypharmacy (χ²=24.339, df=9, p=0.004); this association was considered exploratory because some clinical-condition categories contained relatively small numbers. A strong statistically significant association was observed between polypharmacy and ADR occurrence (χ²=62.983, df=1, p<0.001). ADRs occurred in 105 of 294 patients (35.7%) with polypharmacy compared with 44 of 406 patients (10.8%) without polypharmacy. The odds of an ADR were approximately 4.57 times higher among patients with polypharmacy (OR=4.57, 95% CI: 3.08–6.77). No statistically significant association was observed between polypharmacy and ADR severity (χ²=1.507, df=2, p=0.471). Age group was significantly associated with ADR occurrence (χ²=34.215, df=3, p<0.001), with ADR occurrence of 10.0%, 16.3%, 33.7%, and 35.6% across the four age groups, respectively. Sex was not significantly associated with polypharmacy (χ²=0.493, df=1, p=0.483) or ADR occurrence (χ²=0.020, df=1, p=0.888).

TABLE 10. ASSOCIATION BETWEEN SELECTED VARIABLES