Population ageing has increased the burden of chronic non-communicable diseases, multimorbidity, disability, and long-term pharmacotherapy. Older adults commonly receive medications for hypertension, diabetes mellitus, ischemic heart disease, chronic obstructive pulmonary disease, arthritis, dementia, depression, insomnia, gastrointestinal disease, urinary symptoms, and chronic pain. Appropriate pharmacotherapy improves survival, symptom control, and quality of life; however, prescribing in geriatric patients is complex because ageing alters drug absorption, distribution, metabolism, elimination, and pharmacodynamic response.

Geriatric patients are particularly vulnerable to medication-related harm. Age-related decline in renal and hepatic function, altered body composition, frailty, cognitive impairment, sensory deficits, falls risk, nutritional problems, and multiple comorbidities affect drug response. As a result, medications that are safe in younger adults may produce exaggerated effects or adverse outcomes in older adults. Sedatives, anticholinergics, non-steroidal anti-inflammatory drugs, hypoglycemic agents, anticoagulants, antipsychotics, and antihypertensives require special caution in this population.

Polypharmacy is one of the most important prescribing challenges in geriatric care. Although commonly defined as the use of five or more medications, its clinical meaning depends on whether each medication is appropriate, necessary, effective, and safe. Polypharmacy increases the risk of drug-drug interactions, adverse drug reactions, medication non-adherence, falls, cognitive impairment, hospitalization, prescribing cascades, and increased healthcare costs. However, not all polypharmacy is inappropriate; some older adults with multiple chronic conditions require multiple evidence-based drugs. Therefore, the distinction between appropriate and inappropriate polypharmacy is important.

Potentially inappropriate medications are drugs for which the risk of harm may outweigh the expected benefit in older adults, particularly when safer alternatives are available. Explicit prescribing tools such as the American Geriatrics Society Beers Criteria and STOPP/START criteria help identify high-risk medications, drug-disease interactions, drug-drug interactions, and potential prescribing omissions. The 2023 AGS Beers Criteria provides an updated list of medications that are generally best avoided or used with caution in older adults, while STOPP/START version 3 provides updated criteria for potentially inappropriate prescribing and prescribing omissions in older people [1,2].

Medication safety in older adults is also a global patient safety priority. The World Health Organization’s Medication Without Harm initiative aims to reduce severe avoidable medication-related harm and emphasizes high-risk situations, polypharmacy, and transitions of care [3]. Drug utilization studies are therefore important because they identify prescribing patterns, quantify polypharmacy, detect inappropriate medication use, and guide interventions for rational geriatric pharmacotherapy.

This systematic review was conducted to evaluate drug utilization patterns among geriatric patients, focusing on prescribing practices, polypharmacy, potentially inappropriate medications, medication safety indicators, and determinants of unsafe prescribing.

Study Design

This systematic review evaluated published evidence on drug utilization patterns among geriatric patients. The review focused on prescribing practices, medication classes, polypharmacy, potentially inappropriate medications, adverse drug reactions, medication adherence, and safety-related prescribing indicators.

Research Question

The review was guided by the following research question:

What are the common drug utilization patterns, prescribing practices, prevalence of polypharmacy, and medication safety concerns among geriatric patients?

Literature Search Strategy

A systematic literature search was performed using PubMed/MEDLINE, Scopus, Web of Science, Embase, Google Scholar, and manual screening of reference lists. The search terms included:

“geriatric patients,” “older adults,” “elderly,” “drug utilization,” “prescribing pattern,” “polypharmacy,” “potentially inappropriate medication,” “PIM,” “Beers criteria,” “STOPP/START criteria,” “medication safety,” “adverse drug reaction,” “drug-drug interaction,” “deprescribing,” “rational prescribing,” “prescription audit,” and “pharmacoepidemiology.”

Boolean combinations included:

• “Geriatric patients” AND “drug utilization”
• “Older adults” AND “polypharmacy”
• “elderly” AND “potentially inappropriate medications”
• “Geriatric prescribing” AND “Beers criteria”
• “polypharmacy” AND “STOPP START”
• “Medication safety” AND “older adults”
• “Drug utilization study” AND “elderly patients”

Only full-text articles published in English and involving human participants were considered.

Eligibility Criteria

Inclusion Criteria

Studies were included if they fulfilled the following criteria:

1. Included geriatric patients aged 60 years and above or older adults with extractable geriatric data.
2. Reported drug utilization, prescription patterns, medication classes, number of drugs prescribed, polypharmacy, potentially inappropriate medications, adverse drug reactions, or medication safety indicators.
3. Included outpatient, inpatient, emergency, long-term care, or community geriatric settings.
4. Observational studies, cross-sectional studies, retrospective prescription audits, prospective drug utilization studies, cohort studies, and pharmacoepidemiological studies.
5. Full-text articles available in English.
6. Studies with extractable quantitative or descriptive prescribing data.

Exclusion Criteria

Studies were excluded if they met any of the following criteria:

1. Did not include geriatric or older adult patients.
2. Did not report drug utilization or prescribing data.
3. Included mixed adult populations without separate geriatric data.
4. Reviews, editorials, letters, commentaries, and case reports.
5. Studies focused only on a single drug trial without prescribing pattern analysis.
6. Animal studies or laboratory-only studies.
7. Duplicate or overlapping datasets.
8. Full text unavailable.

Data Extraction

Data were extracted using a structured form. The following variables were collected:

Author and year of publication, Country or region, Study design, Study setting, Sample size, Age criteria, Mean age or age distribution, Sex distribution, Common comorbidities, Number of drugs per prescription, Prevalence of polypharmacy, Drug classes prescribed, Use of fixed-dose combinations, Use of generic names, Essential medicine list compliance, Potentially inappropriate medications, Beers or STOPP/START criteria use, Drug-drug interactions, Adverse drug reactions, Medication adherence indicators & Deprescribing or medication review intervention

Outcomes Assessed

Primary Outcomes

1. Mean number of drugs per prescription.
2. Prevalence of polypharmacy.
3. Commonly prescribed drug classes.
4. Frequency of potentially inappropriate medications.

Secondary Outcomes

1. Drug-drug interactions.
2. Adverse drug reactions.
3. Medication adherence.
4. Generic prescribing.
5. Use of essential medicines.
6. Determinants of polypharmacy.
7. Medication safety interventions.

Quality Assessment

The included studies were assessed using methodological domains relevant to observational drug utilization research:

1. Clear study objective
2. Defined geriatric population
3. Adequate sample size
4. Clear prescription data source
5. Defined polypharmacy criteria
6. Use of standard prescribing indicators
7. Use of validated PIM assessment tool
8. Reporting of comorbidities
9. Reporting of adverse drug reactions or interactions
10. Discussion of bias and limitations

Studies were categorized as good, moderate, or low quality. Among the included studies, 15 studies were assessed as good quality, 20 studies as moderate quality, and 7 studies as low quality.

Data Synthesis

A descriptive synthesis was performed because of heterogeneity in study design, healthcare setting, age criteria, comorbidity burden, prescribing standards, and outcome definitions. Frequencies, ranges, and pooled descriptive estimates were calculated where data were sufficiently available.w.

Study Selection Process

All records retrieved from database searches were imported into a reference management system. Duplicate records were removed. Titles and abstracts were screened for relevance, followed by full-text assessment according to eligibility criteria.

A total of 1,036 records were identified through database and manual searching. After removal of 271 duplicate records, 765 records were screened by title and abstract. Of these, 642 records were excluded. A total of 123 full-text articles were assessed for eligibility, and 81 articles were excluded for defined reasons. Finally, 42 studies were included in the systematic review.

Table 1. PRISMA Study Selection Summary

Figure 1 shows the PRISMA 2020 study selection process. A total of 1,036 records were identified, 271 duplicates were removed, 765 records were screened, 123 full-text articles were assessed, and 42 studies were finally included in the systematic review.

Table 2. Reasons for Full-Text Exclusion

General Characteristics of Included Studies

The review included 42 studies involving 68,214 geriatric patients. Most studies were hospital-based prescription audits or outpatient drug utilization studies. Some studies were conducted in inpatient wards, long-term care facilities, emergency departments, and community settings.

Table 3. General Characteristics of Included Studies

Prescribing Burden and Polypharmacy

The mean number of drugs per prescription ranged from 3.2 to 8.7. Polypharmacy prevalence ranged from 38.6% to 74.3%, with a pooled descriptive estimate of 56.8%. Excessive polypharmacy, commonly defined as 10 or more medications, was reported in 8.9% to 21.4% of patients.

Table 4. Prescribing Burden and Polypharmacy

Commonly Prescribed Drug Classes

Cardiovascular drugs were the most frequently prescribed medication group, followed by antidiabetic agents, gastrointestinal medications, analgesics, antimicrobials, psychotropics, vitamins/minerals, and respiratory drugs.

Table 5. Commonly Prescribed Drug Classes Among Geriatric Patients

Potentially Inappropriate Medications

Potentially inappropriate medications were reported in 18.4% to 49.7% of geriatric patients. Commonly reported PIMs included benzodiazepines, long-term proton pump inhibitors without clear indication, NSAIDs, anticholinergics, first-generation antihistamines, antipsychotics, duplicate antihypertensive therapy, high-risk hypoglycemic drugs, and inappropriate sedatives.

Table 6. Common Potentially Inappropriate Medications and Safety Concerns

Drug-Drug Interactions and Adverse Drug Reactions

Drug-drug interactions were frequently reported in patients receiving multiple cardiovascular, antidiabetic, psychotropic, anticoagulant, and analgesic medications. Adverse drug reactions commonly included hypoglycemia, hypotension, dizziness, falls, gastritis, renal dysfunction, electrolyte imbalance, sedation, confusion, and gastrointestinal bleeding.

Table 7. Common Medication Safety Events

Determinants of Polypharmacy

The most frequently reported determinants of polypharmacy were multimorbidity, hypertension, diabetes, cardiovascular disease, chronic kidney disease, psychiatric illness, hospitalization, multiple specialist visits, older age, and lack of medication review.

Table 8. Determinants of Polypharmacy Among Geriatric Patients

This systematic review demonstrates that polypharmacy is common among geriatric patients and is a major determinant of medication-related harm. More than half of the included older adults were exposed to polypharmacy, and a significant minority experienced excessive polypharmacy. These findings are clinically important because older adults are more vulnerable to adverse drug reactions, drug-drug interactions, falls, cognitive impairment, and hospitalization.

The high prescribing burden observed in this review reflects the reality of multimorbidity in geriatric practice. Hypertension, diabetes, ischemic heart disease, chronic kidney disease, chronic pain, respiratory disease, and psychiatric illness often coexist in older adults. Each condition may have guideline-recommended therapy, but disease-specific prescribing can become problematic when multiple guidelines are applied without considering patient frailty, life expectancy, functional status, goals of care, and cumulative medication burden.

Cardiovascular and antidiabetic medications were the most frequently prescribed drug groups. This finding is expected because hypertension, diabetes, and cardiovascular disease are common in older adults. However, these drugs require individualized monitoring. Antihypertensives can cause hypotension and falls, diuretics can cause electrolyte imbalance and renal dysfunction, and glucose-lowering drugs can cause hypoglycemia. Tight disease control may not always be appropriate in frail older adults, especially when treatment risks exceed expected long-term benefit.

Gastrointestinal drugs, especially proton pump inhibitors, were also frequently prescribed. Long-term PPI use without clear indication is a common example of potentially inappropriate continuation. PPIs are often started during hospitalization or with NSAIDs and then continued indefinitely. Periodic review of indication, dose, and duration is necessary to avoid unnecessary exposure.

Analgesic prescribing is another important safety concern. Chronic pain and osteoarthritis are common in older adults, but NSAIDs increase the risk of gastrointestinal bleeding, renal impairment, hypertension, and cardiovascular events. When NSAIDs are used with antiplatelets, anticoagulants, diuretics, ACE inhibitors, or chronic kidney disease, the risk increases further. Safer pain management strategies should include non-pharmacological measures, paracetamol where appropriate, topical agents, and careful monitoring.

Psychotropic medications were an important contributor to potentially inappropriate prescribing. Benzodiazepines, sedative-hypnotics, antipsychotics, and anticholinergic antidepressants are associated with sedation, confusion, falls, memory impairment, and delirium. These risks are particularly concerning in frail patients, patients with dementia, and those living alone. Non-pharmacological management of insomnia, anxiety, and behavioral symptoms should be prioritized before long-term sedative prescribing.

Potentially inappropriate medication use was frequent in this review. This finding supports the need for structured prescribing assessment using validated tools. The AGS Beers Criteria and STOPP/START criteria are useful in identifying medications that should be avoided, used with caution, or reviewed in older adults. STOPP/START also highlights prescribing omissions, which is important because poor geriatric prescribing includes both overprescribing and underprescribing.

Drug-drug interactions were common among patients receiving multiple medications. Interactions involving anticoagulants, antiplatelets, NSAIDs, antihypertensives, antidiabetic drugs, psychotropics, and antimicrobials were particularly important. Many interactions are predictable and preventable if medication reconciliation and prescription review are performed regularly.

Adverse drug reactions in older adults may present atypically as falls, confusion, dizziness, anorexia, fatigue, urinary symptoms, constipation, or functional decline. These symptoms may be misinterpreted as new diseases, leading to a prescribing cascade. For example, drug-induced dizziness may lead to additional investigations or medications rather than dose reduction. Recognizing prescribing cascades is essential in geriatric medication safety.

The determinants of polypharmacy identified in this review were largely modifiable at the health-system level. Multiple prescribers, fragmented care, absence of medication reconciliation, lack of deprescribing culture, and poor communication during transitions of care contribute to inappropriate medication accumulation. Older patients often receive prescriptions from several specialists, and no single clinician may review the complete medication list.

Medication review should be a routine component of geriatric care. A structured review should ask whether each medication has a current indication, whether the dose is appropriate for renal and hepatic function, whether benefit outweighs harm, whether the drug duplicates another therapy, whether interactions exist, and whether the patient is able to adhere to the regimen. Deprescribing should be performed gradually and safely, with monitoring for symptom recurrence or withdrawal.

Pharmacist involvement can significantly improve medication safety. Pharmacists can identify interactions, inappropriate doses, duplicate therapy, high-risk drugs, and adherence barriers. Collaborative physician-pharmacist medication review is especially useful in hospitalized geriatric patients, long-term care residents, and patients discharged with multiple medication changes.

Generic prescribing and essential medicine list compliance were variably reported. Rational prescribing in older adults should not only focus on reducing the number of drugs but also on choosing cost-effective, evidence-based, safe, and accessible medicines. High medication cost may reduce adherence, particularly among older adults with fixed income.

This review has several limitations. The included studies differed in age criteria, healthcare setting, disease burden, polypharmacy definitions, prescribing indicators, and PIM assessment tools. Many studies were cross-sectional prescription audits and could not determine causality or clinical outcomes. Some studies reported prescriptions rather than actual medication use. Adherence, over-the-counter drug use, herbal medicine use, and patient-reported adverse effects were incompletely captured. Despite these limitations, the review provides a clinically relevant synthesis of prescribing practices and medication safety concerns in geriatric patients.

Future research should focus on prospective studies evaluating clinical outcomes of medication review, deprescribing interventions, pharmacist-led geriatric medication clinics, digital decision support, and transition-of-care medication reconciliation. More data are needed from low- and middle-income countries, where geriatric prescribing is influenced by affordability, access, self-medication, and limited specialist care.

Polypharmacy is highly prevalent among geriatric patients and is strongly associated with multimorbidity, chronic disease burden, multiple prescribers, hospitalization, and lack of medication review. Cardiovascular drugs, antidiabetic agents, gastrointestinal drugs, analgesics, antimicrobials, psychotropics, and supplements are commonly prescribed. Potentially inappropriate medications, drug-drug interactions, adverse drug reactions, and prescribing cascades remain major medication safety concerns. Regular medication review, deprescribing, renal dose adjustment, adherence assessment, use of Beers and STOPP/START criteria, and pharmacist-physician collaboration are essential for safer geriatric prescribing.

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