DRUG UTILIZATION STUDY AMONG GERIATRIC PATIENTS IN A TERTIARY CARE TEACHING HOSPITAL IN SOUTH INDIA

Objectives: The objective of our study is to evaluate the drug utilization pattern among geriatric patients in a tertiary care teaching hospital in South India and analyze the prescription pattern. Methods: Retrospective medical record analysis was performed for indoor cases of the geriatric patients (aged ≥65 years) admitted in medicine wards of Raichur Institute of Medical Sciences teaching hospital, Raichur, from June 2015 to May 2016. They were analyzed for demo graphics, disease pattern by system involved, disease diagnosed, comorbidity pattern, most commonly prescribed drugs, distribution of drugs according to their therapeutic class, evaluation of polypharmacy, route of administration, fixed-dose combinations, and the World Health Organization core prescribing indicators. Results: A total of 400 prescriptions of geriatrics patients admitted in inpatient medicine department were randomly selected and all the required data for the study were collected and evaluated. The majority of patients were found to be in the age group of 65–70 years (70.25%). It was noticed that females (51.75%) were more compared to males (48.25%). The drugs prescribed were analyzed. Ranitidine, ceftriaxone, theophylline, and salbutamol were prescribed to majority of the patients in this study group. The average number of drugs per prescription was 7.42; drugs prescribed by generic name were 33.62%. Among the drugs prescribed, 88.69% were from the National List of Essential Medicines. Total encounters having injectable preparations were 100% and total encounters having antibiotic prescribed were 91%. The prevalence of cardiovascular disorders (32.5%) was high followed by respiratory disorders (32.25%). This study insight into the on patients as well as various diseases prevalent among geriatric patients. Widespread polypharmacy, high use of antibiotics and injections, and lack of generic prescribing are some concerns that need to be addressed to promote rational usage of drugs.


INTRODUCTION
India is aging fast and the geriatric population is currently about 7% of the total population [1] and it is increasing throughout the world with a growth rate of 1.9% which is more than the general population growth rate, i.e., 1.2%. At present, India is the third country after China and the USA with large elderly population in the world [2]. The age of 65 and above is considered as geriatrics, studying on geriatrics is called gerontology [3]. Geriatric medicine is the branch of medicine which deals with clinical and medical aspects of gerontology.
Physiological and pharmacological variations that occur with aging are changes in the gastrointestinal (GI) absorption, reduced absorption from the skin, shrinkage of liver with reduced hepatic blood flow, slower elimination of fat-soluble drugs as the body fat increases in proportion to water and muscle, impaired renal function, reduced glomerular filtration rate, and down or upregulation of various receptors [1]. Such variations affect the usage of drugs in them.
Geriatric patients suffer from multiple diseases and hence, need multiple drugs which increase the risk of adverse drug reactions, drug interactions, irrational prescribing, cost burden, and patient noncompliance. Such problems in their therapy can be solved by regular drug utilization evaluation, by standardizing the prescribing pattern by making prescription guidelines for geriatric patients [2] and by regular prescription checking or else it will cause serious consequences regarding their medications use [3].
Even though geriatric patients consume half of the total drug usage, very few randomized control trials (<5%) have been planned on them, so whatever data available from young subjects are used to formulate prescribing pattern for them [2]. Not much research work is carried out to study the prescribing pattern among the elderly and our study, especially involving geriatric patients, has tried to study their medications use to promote rational usage of drugs among them.

Ethical issues
The study was approved by the Institutional Ethical Committee of Raichur Institute of Medical Sciences (RIMS) -Raichur, a tertiary care teaching hospital.

Patient selection criteria
Patients of either sex aged 65 years and above admitted in medicine inward unit were included in the study. Patients who went away against medical advice, patients on ventilators, or seriously ill patients were excluded from the study.

Study design and area
Our study was a retrospective observational hospital-based drug utilization study on the geriatric patients of the Medicine Department of RIMS tertiary care teaching hospital, Raichur, India.

Study population
The present study was conducted on 400 geriatric patients who were admitted in the male and female medical wards of RIMS tertiary care hospital -Raichur, India.

Study methodology
The study was carried out by regular visits to medical record section of RIMS tertiary care hospital, Raichur, and case sheets of patients of above 65 years of age admitted in medicine ward over a period of 1 year from June 2015 to May 2016 were collected. The relevant data collected from case sheets were properly documented in a separate data collection form. The obtained data were then analyzed for demographic characteristics such as gender distribution, age-wise distribution, reason of admission, number of stay in hospital, distribution of comorbidities, oral and parenteral formulations, category-wise distribution of drugs, and most commonly prescribed drugs.
Drugs prescribed were then analyzed using the World Health Organization (WHO) core prescribing indicators which include mean number of drugs per prescription, use of drugs by generic and brand names, patients prescribed with antibiotics and injections, medications prescribed from the National List of Essential Medicines (NLEM).

Statistical analysis
The statistical analysis was done using the Excel software package. The data were subjected to descriptive analysis using Microsoft Excel. Drugs were verified by NLEMs 2015. Different parameters were given as a percentage and results were expressed as percentage comparison.

RESULTS
In the present study, a total of 400 prescriptions of geriatrics patients admitted in inpatient medicine department were randomly selected and all the required data for the study were collected and evaluated. The enrolled patients were distributed according to gender and age. Among the study population, a total of 2971 formulations were prescribed with an average of 7.42 drugs per prescription. The following parameters were analyzed and evaluated during the study:

Socio-epidemiological data
• Gender-wise distribution • Age-wise distribution 2. Disease or disorder pattern by system involved 3. Disease or disorder diagnosed 4. Comorbidity pattern 5. The WHO core prescribing indicators 6. Most commonly prescribed drugs 7. Distribution of drugs according to their therapeutic class 8. Evaluation of polypharmacy 9. Duration of stay 10. Route of administration and 11. Fixed-dose combinations (FDCs).

Socio-epidemiological data
Among 400 patients, female (51.75%) predominance was observed in comparison of male (48.25%) patients. The majority of patients were in the age group of 65-70 years (70.25%) as depicted in Table 1.

Disease or disorder pattern by system involved
Among the study population, the prevalence of cardiovascular disorders (32.5%) was high, followed by respiratory disorders (32.25%), central nervous system disorders (19%), and GI disorders (10.5%) as depicted in Table 2.

Comorbidity pattern
Majority of patients 318 (79.5%) in our study were found suffering with one disease, 72 patients (18%) were found with two diseases, 9 patients (2.25%) were found suffering with three diseases, and only 1 patient (0.25%) was suffering from four diseases.

WHO core prescribing indicators
A total of 2971 drugs were prescribed to the study population with an average of 7.42 drugs per prescription. Only 33.62% of drugs were prescribed by their generic name. The percentage of prescribed drugs from NLEM (2015) was found to be 88.69%. Encounters with antibiotics and injectables were found to be 91% and 100%, respectively ( Table 3).

Ten most commonly prescribed drugs
Ranitidine (95.75%) was found to be the most commonly prescribed drug to the study population. Among antibiotics, ceftriaxone (67.5%) was most frequently prescribed drug. Among respiratory drugs to treat asthma and chronic obstructive pulmonary disease (COPD), theophylline (36%) and salbutamol (34.75%) were frequently   used drugs and among intravenous (IV) fluids, ringer lactate (33%) and normal saline (29.5%) were frequently prescribed and among cardiovascular drugs, aspirin (23.25%) was most commonly used drug ( Table 4).

Polypharmacy
A total of 2971 drugs with an average of 7.42 drugs per prescription were prescribed to the study population. 6-10 drugs were prescribed in majority 314 (78.5%) of prescriptions followed by 3-5 drugs were prescribed to 63 prescriptions (15.75%) and >10 drugs were prescribed in 23 (5.75%) prescriptions ( Table 5).

Duration of stay
For majority (57.25%) of patients, duration of stay was 0-5 days followed by 6-10 days for 36% of patients (Table 6).
Detail about the number of antibiotics prescribed to the patient, route of administration of drugs and FDCs prescribed are enlisted in Tables 7-9, respectively.

DISCUSSION
Due to aging, elderly people are more vulnerable to various diseases with several comorbidities. To treat the multiple diseases, multidrug therapy is used and this leads to the use of multiple drugs. The chances of drug-drug interaction are high due to multiple drug therapy. It is estimated that the incidence of polypharmacy is higher among geriatric people as compared to other age group population.
In this study, the numbers of female (51.75%) patients are high as compared to males (48.25%) which is similar to the study done by Nayaka et al. [5] which showed female majority, whereas in other studies conducted by Ramanath and Nedumballi [6], Pradhan et al. [7], and Singh [4], male patients were high. Maximum patients were in the age group of 65-70 years (70.25%) which is same like studies conducted by Burla [8] and Nayaka et al. [5], wherein the maximum patients were in the age group of 60-70 years.
The prevalence of cardiovascular disorder is high in our study (32.5%) followed by respiratory disorders (32.25%) and central nervous system disorders (19%), which is similar to the studies conducted by John and Kumar [9], Jhaveri et al. [2], and Singh [4]. Whereas in other studies conducted by Jafrin et al. [1] and Goudanavar et al. [10], respiratory disorders were more common than cardiovascular disorders. Cardiovascular disorders accounted for more hospitalization in our study, among them, hypertension (15.75%) and ischemic heart disease (10.75%) are most common and in respiratory disorders, the prevalence of COPD (15%) is high.
Majority of patients in our study are suffering from a single disease (79.5%). The presence of comorbidities is very low in our study with one comorbidity found in 18% of patients, followed by two comorbidities in 2.25% and three comorbidities in only 1 patient. The most common comorbidity was hypertension, whereas in a study conducted by Nayaka et al. [5], majority 66% had a single comorbid disease.
Ondansetron 91 (22.75)    Other route of administration 141 4.74  [12]. The reason for the high use of injections could be that our study was done in a tertiary care hospital where patients with chronic and serious conditions are treated, an injectable form is necessary to produce a faster onset of action. Injections are very expensive compared to other dosage forms and require trained personnel for administration [11].
A total of 2971 drugs were prescribed in all the cases with 64.45% parenteral, 30.79% oral, and 4.74% other formulations. These findings are similar to a study conducted by Balaji et al. [17] with 51% parenteral, 35% oral preparation, and 8% other formulations.
Of 2971 drugs prescribed, 254 (8.5%) were FDCs, which is less when compared to other studies such as 25% FDCs in Sharma et al. [12] and 17% in Nayaka et al. [5]. Most common FDCs prescribed were of theophylline+etophylline and salbutamol + budesonide. However, considering that the number of FDCs in India, which is around 60% of all available formulations, the use of FDCs in our institution is relatively low, reflecting the rational use of medicines [5]. It is also important to note that inappropriate use of drugs represents a potential hazard to the patients and an unnecessary expense [18].

CONCLUSION
This study provides insight into the patterns of drug use in our tertiary care hospital on geriatric patients. The assessment of drugs by the WHO core prescribing indicators will help to improve the prescribing pattern and even to minimize the cost burden of patients. The percentage of medications prescribed from NLEM is very good in our study, but the use of injections and antibiotics was high. The percentage of prescribing by generic name was low, and efforts to encourage prescribing by generic name should be initiated. The average number of drugs per prescription was high, suggesting polypharmacy and inappropriate medication use.
Hence, continuous medical education with a focus on rational drug use and evidence-based medicine should form a part of the program of our hospital. In future, a multidisciplinary approach should be taken involving physicians, nurses, and pharmacists. They have to work as a team for bringing out rational drug use in the geriatric population.