International Journal of Health & Allied Sciences

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 7  |  Issue : 4  |  Page : 222--227

A study on polypharmacy and drug interactions among elderly hypertensive patients admitted in a tertiary care hospital


Rajat Kumar Agrawal1, Shailesh Nagpure2,  
1 Final MBBS Part-II Jawaharlal Nehru Medical College, DMIMS (DU), Wardha, Maharashtra, India
2 Department of Pharmacology, Jawaharlal Nehru Medical College, Wardha, Maharashtra, India

Correspondence Address:
Dr. Shailesh Nagpure
Department of Pharmacology, Jawaharlal Nehru Medical College, Wardha - 442 001, Maharashtra
India

Abstract

BACKGROUND: Polypharmacy may be defined as the effects of taking multiple medications concurrently to manage coexisting health problems, such as diabetes and hypertension. Polypharmacy is an important issue in elderly patients. METHODS: A cross-sectional study was conducted in the rural tertiary care teaching hospital in Central India over 2 months. A total of 100 patients were studied. The study population included hypertensive geriatric population above 65 years admitted in the medicine ward who were willing to consent for participation. The patients with incomplete case sheets admitted in the Emergency and Intensive Care Units and with serious illness, malignancy, and other complications were excluded. RESULTS: Out of the total 403 medicine prescribed to study population, 271 potential drug–drug interactions were observed among elderly hypertensive patients. Moderate drug–drug interaction was found to be most common (50.62%) followed by mild (8.64%) and severe (7.94%). Most common potential inappropriate medicine used was spironolactone followed by diltiazem, diclofenac, olanzapine, metoclopramide, digoxin, insulin, and isopto hyoscine (Sliding scale) in the study population. CONCLUSION: In the present study, we can conclude that polypharmacy is a major risk factor for secondary morbidity in elderly patients. Polypharmacy leads to more potential drug–drug interactions and potential inappropriate medicine use. The use of medicines to disease condition is necessary, but unnecessary load of drugs to patient will increase the safety problems. Polypharmacy can be avoided by sharing treatment goals and plans. To improve drug safety in this high-risk population, appropriate prescribing might be more important than simply reducing the number of prescribed drugs.



How to cite this article:
Agrawal RK, Nagpure S. A study on polypharmacy and drug interactions among elderly hypertensive patients admitted in a tertiary care hospital.Int J Health Allied Sci 2018;7:222-227


How to cite this URL:
Agrawal RK, Nagpure S. A study on polypharmacy and drug interactions among elderly hypertensive patients admitted in a tertiary care hospital. Int J Health Allied Sci [serial online] 2018 [cited 2018 Dec 9 ];7:222-227
Available from: http://www.ijhas.in/text.asp?2018/7/4/222/243264


Full Text



 Introduction



The aging process is a biological reality which has its own dynamic, largely beyond human control. Aging is a natural process. The word “Geriatric” refers to old age people and also Geriatrics or geriatric medicine is a specialty that focuses on health care of elderly people. It aims to promote health by preventing and treating diseases and disabilities in older adults with improvement in medical services in the last few years; there has been a constant rise in the geriatric population throughout the world, more so in the developing countries.[1],[2] According to recent statistics related to elderly people in India, in the year 2001, it was observed that as many as 75% of elderly persons were living in rural areas. About 48.2% of elderly persons were women.[3],[4],[5] In India, the elderly people suffer from dual medical problems, that is, both communicable as well as non-communicable diseases. In the population over 70 years of age, >50% suffer from one or more chronic conditions. The chronic illnesses usually include hypertension, coronary heart disease, and cancer.[6],[7],[8],[9],[10],[11] Polypharmacy may be defined as the effects of taking multiple medications concurrently to manage coexisting health problems, such as diabetes and hypertension. Polypharmacy is an important issue in elderly patients.[4],[5],[6],[7] Multiple comorbidities are one of the important reasons for polypharmacy in elderly population. Multimorbidity in the elderly has been estimated to range from 55% to 98% and is highest in the oldest and individuals belonging to low socioeconomic classes.[12],[13],[14],[15] This practice of polypharmacy in elderly patients may lead to certain drug–drug interaction, which may hamper the effectiveness of treatment provided to the patients, ultimately increases the burden of health care providers and facilities with the purpose of finding such hazards associated with polypharmacy in elderly patients this study is planned.[16],[17],[18],[19],[20],[21]

 Methods



A cross-sectional study was conducted at Acharya Vinoba Bhave Rural Hospital (AVBRH), one of the rural tertiary care teaching hospital in Central India. Duration of the study was 2 months. A total of 100 patients were studied over this duration. All hypertensive geriatric population above 60 years willing to give consent of either sex with hypertension admitted in medicine ward of tertiary care hospital were included in this study and those with incomplete case sheet and with serious illness, malignancy, and other complications were excluded from the study. The study was planned to assess polypharmacy and drug–drug interactions among elderly hypertensive patients and objectives were to assess the polypharmacy among elderly hypertensive patients admitted in medicine ward at AVBRH, to find out the prevalence of drug–drug interactions among elderly hypertensive patients undergoing polypharmacy, to find out potentially inappropriate drugs being prescribed using “Beers Criteria.” Data were collected from review of case sheets of all elderly hypertensive patients admitted in the Department of Medicine. Case sheets of all the admitted elderly hypertensive patients from the hospital were reviewed by the study investigator each day during the study period. Such review of case sheets was considered only once for each patient during one single admission. Any patient may be admitting more than once during the study period. In such situation, each admission-case sheet was considered as a separate admission.

 Results



The total study population was classified into three age groups 60–79, 70–79, and 80–89. Most common elderly patients admitted during the study period were between the age group 60–79 years followed by 70–79 years and represents 60% and 31% of total study population, respectively. Elderly patients 80–89 years were admitted in less number and represents 9% of the total study population. Minimum age of elderly patient admitted in medicine department was 60 years and maximum was 87 year [Table 1] and [Figure 1].{Table 1}{Figure 1}

Out of the total study population, 100 elderly patients admitted in the hospital during the study period, 39 (39%) were male and 61 (61%) were female. The mean age of patients was 67.31 ± 7.05 years [Table 2] and [Figure 2].{Table 2}{Figure 2}

Mean number of drugs prescribed to the study population admitted in medicine department was (4.03 ± 1.80). Out of this ≤4 number of drugs were prescribed to 74% population, 5–9 number of drugs were prescribed to 25% population, and 10–14 number of drugs were prescribed to 1% population [Table 3] and [Figure 3].{Table 3}{Figure 3}

60–69 years age group have been prescribed with 239 number of drugs in the study population, while 70–79 years and 80–89 years age groups have been prescribed with 128 and 30 number of drug, respectively [Table 4] and [Figure 4].{Table 4}{Figure 4}

Out of total 403 medicines prescribed to the study population, 271 (67.24%) potential drug–drug interactions were observed among elderly hypertensive patient [Table 5] and [Figure 5].{Table 5}{Figure 5}

Most common drug–drug interactions observed in the study population were of moderate grade 50.62%, Mild drug–drug interactions were 8.64% whereas severe drug–drug interactions were 7.94% [Table 6] and [Figure 6].{Table 6}{Figure 6}

Out of 403 number of drug prescribed to the study population, total number of potential inappropriate medicine was 8 in number, i.e., 1.98% [Table 7] and [Figure 7].{Table 7}{Figure 7}

Most common potential inappropriate medicine used was spironolactone followed by diltiazem, diclofenac, olanzapine, metoclopramide, digoxin, insulin, and isopto hyoscine (Sliding scale) in the study population [Table 8] and [Figure 8].{Table 8}{Figure 8}

 Discussion



In this study, majority of patients admitted in the department of medicine are between age group 65–69 and number of patients admitted decline with age. More numbers of drugs are prescribed to the age group between 60 and 69 years. Our study findings are similar to the study findings by Armugam A in which more drugs were prescribed to age group ≥75 years of age. However, our results are contradicting to study done by David Baumgartner, in which there was also increase in the mean number of drugs prescribed to the older elderly.

Mean number of drugs prescribed to admitted elderly patients were 4.03 ± 1.80. Out of this, ≤4 number of drugs were prescribed to 74% population, 5–9 number of drugs were prescribed to 25% population and 10–14 number of drugs was prescribed to 1% population. Our study results are similar to the study conducted by Armugam et al. and Schuler et al. Both of them observed polypharmacy in >55% of admitted elderly. According to the Kaufman, the use of >5 drugs means polypharmacy. polypharmacy in our study observed was higher than that reported internationally. Polypharmacy might be due to patient was not responding to treatment so more options of drugs used by the physician to treat the patient. There was number of potential drug–drug interactions observed in this study. Online drugs interaction checker of drugs.com was reported interaction in the vast majority of patients. Of the total 403 drugs prescribed in elderly 67.24% drugs can cause potential drug–drug interactions. The drug–drug interactions were found more when more drugs were prescribed to the elderly patients. In our study, the most common potential drugs interaction were of moderate grade (50.62%). Potentially severe drug interactions are (7.94%) of total potential drug–drug interactions. We found more potential drug–drug interactions when compared to a study conducted by Björkman et al. in 2002, in which there were drug interactions in 46% of patients. Furthermore, a study conducted by Gosney M showed potential drug–drug interactions in 33% of all prescriptions in admitted elderly patients.

In variety of studies, different computerized drug–drug interaction programs were used to found out drug interactions. Studies those assessing actual drug interactions, that is, with an adverse patient outcome from as a result of drug interaction should be separated from those looking at potential drug–drug interactions. The risk of drug–drug interactions rises almost exponentially with number of drugs prescribed as there are more pairs of drugs to interact. In general, the prevalence of clinically relevant drug interactions is about 6% in patients taking two to four medications, 50% in those taking five and almost 100% in those taking 10 medications. Hence, in our study also, we observed potential drug–drug interaction in >50% of patients. Several studies testing the performance of drug interaction software found low levels of sensitivity and specificity, but more recent studies indicate that sensitivity and specificity have improved.

Beers criteria are very frequently used method for evaluating appropriateness of prescribing in elderly. It was developed in 1999 and recently updated by American Geriatric Society in 2012. In our study, potentially inappropriate medicines prescribed were 1.98% of total prescribed drugs in elderly patients. A study conducted in South India by Harugeri observed potentially appropriate medicines in 22.1% patient at admission conducted in South India which is higher than our study findings. In addition, our study findings are contradicting to the study conducted by a Rothberg et al. in 2008 in which he observed at least 1 potential appropriate medicine in 49% patients. However, our study findings are similar to study conducted by Veena et al. in 2012 in which she observed 4.33% of patients. One reason for contradicting the results of our study and a study done by Harugeri and Rothburg, the reason may be this study was conducted in limited population in tertiary care hospital and those studies were on large population. The most common potential inappropriate medications used were benzodiazepine and anti-inflammatory group. Insulin also comes under potential inappropriate medicines, but if it is prescribed in sliding scale. Increased number of medications' use may point to the likelihood of exposure to potential inappropriate medicines; it may not necessarily reflect the irrational use of medicines as in few patients and it may be appropriate to use more number of medications. We found the most common groups of drugs prescribed to patients' were nonteroidal anti-inflammatory drugs, calcium channel blockers, cardiac glycosides, antimicrobial agents, and antihypertensive. The nonsteroidal anti-inflammatory drugs are most common prescribed drugs.

Thus, polypharmacy in elderly leads to many problems such as increased chances of drug–drug interactions and use of potential inappropriate medicines, but we cannot avoid it as this population group suffered from many chronic diseases. Raising physician's awareness about polypharmacy and dangerous drug interactions may curb irrational prescriptions and ensure safety of the elderly.

At last, it can be concluded as: this study provided data to assess the prevalence of polypharmacy and dangerous drug–drug interactions among elderly patients. From the present study, we can conclude that polypharmacy is a major risk factor for secondary morbidity in elderly patients. Polypharmacy leads to more potential drug–drug interactions and potentially inappropriate medicine use. The use of medicines to disease condition is necessary, but unnecessary load of drugs to patient will increase the safety problems. Polypharmacy can be avoided by sharing treatment goals and plans. To improve drug safety in this high-risk population, appropriate prescribing might be more important than simply reducing the number of prescribed drugs. Limitations of the study are that it included small population and restriction to one specialty. Larger studies involving elderly patients in various departments are necessary to realize the impact of this serious problem and to make prescriptions more rational in this group of population.

Acknowledgments

The authors would like to thank the Department of Biotechnology under the Ministry of Science and Technology, Govt. of India, for funding the study. (Sanction number BT/Med/15/Vision-NER/2011, dated 2/11/2011, and Memo No. TU/DBT-NC/MD/MS-P7 and 8/14-15/32, dated 27/08/2015). We also thank all the patients who participated in this study.

Financial support and sponsorship

This study was financially supported by the Indian Council of Medical Research.

Conflicts of interest

There are no conflicts of interest.

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