Potential Drug-Drug Interactions and Associated Factors on

Ambulatory Patients with Hypertension of a Secondary Care Hospital

in Bandar Lampung

Noni Zahwa Salsabila, Citra Yuliyanda Pardilawati

, Dwi Aulia Ramdini and Oktafany

Department of Pharmacy, Faculty of Medicine, University of Lampung, Indonesia

Keywords: Hypertension, Drug Interaction, Associated Factor.

Abstract: Hypertensive patients are often given combination therapy according to the patient's condition, the drugs used

have a high risk of potential drug interactions. The aim of this research is to determine potential drug-drug

interactions and associated factors on ambulatory patients with hypertension of a secondary care hospital in

Bandar Lampung. This research is a cross-sectional study. Data were collected from patient’s medical

records. Evaluation of potential drug-drug interactions refers to Drugs.com. The associated factors are

analyzed by Chi-Square test. Of the 135 prescriptions, there are 90 (66,67%) prescriptions that have the

potential for drug-drug interactions. Potential drug-drug interactions based on severity levels are major

(6,88%), moderate (72,10%) and minor (21,01%). Bivariate statistical analysis showed that there was an

influence of age and number of medications on potential drug-drug interactions.

1 INTRODUCTION

Hypertension is a disease condition that occurs due to

an increase in systolic blood pressure exceeding 140

mmHg and diastolic blood pressure exceeding 90

mmHg (Hastuti, 2020). Hypertension is a health

problem in the world because it is a major risk factor

for cardiovascular disease. An estimated 1.28 billion

adults aged 30-79 years worldwide suffer from

hypertension15. Various drugs used to reduce blood

pressure such as diuretics, beta-blockers, ACE

inhibitors, angiotensin II receptor blockers (ARBs),

calcium antagonists, and vasodilators (PERHI, 2021).

This can cause the drugs and antihypertensive therapy

used by hypertension sufferers to vary and there is a

risk of drug interactions (Chalik, 2021).

Drug interactions can cause effects in the form of

increasing or decreasing activity or producing new

effects that were not present before. The occurrence

of drug interactions can also affect the body's

response, thereby affecting the desired therapeutic

outcome (Mahamudu, 2017). Treatment therapy

needs to be carried out optimally by selecting the best

treatment so that it can provide benefits to patients by

improving quality of life (Whittlesea, 2019). One way

that can be done to achieve this goal is to identify,

reduce and prevent potential drug interactions that

can occur, thus having an impact on the success of

therapy (Parulian, 2019).

Therefore, this research was conducted to

determine the potential for drug interactions and the

factors that influence the potential for drug

interactions in hypertensive patients. This research

aims to ensure that potential drug interactions are

more carefully considered and prevented, so the

incidence of drug interactions can be minimized.

2 METHOD

This research is a descriptive-analytic study with a

cross-sectional approach, carried out retrospectively

on the medical records of ambulatory patients with

hypertension of a secondary care hospital in Bandar

Lampung. The data used medical record for the

period January – June 2023. The sample size was

determined using the purposive sampling method.

Determination of the minimum sample size in this

study was determined based on the proportion

estimation formula.

Salsabila, N. Z., Pardilawati, C. Y., Ramdini, D. A. and Oktafany,

Potential Drug-Drug Interactions and Associated Factors on Ambulatory Patients with Hypertension of a Secondary Care Hospital in Bandar Lampung.

DOI: 10.5220/0013101600003873

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 1st International Conference on Medical Science and Health (ICOMESH 2023), pages 21-24

ISBN: 978-989-758-740-5

Explanation:

𝑛: Number of samples

N: Number of populations

Z: Degree of trust

p: The proportion of cases to the population

d: The degree of deviation from the desired population

The population of ambulatory patients with

hypertension of a secondary care hospital in Bandar

Lampung on 2023 is 205 patients. The minimum

sample size for this research is 135 samples. In this

study, the inclusion criteria applied were patients

aged ≥ 18 years and having medical records with

complete information. The exclusion criteria applied

were patient who get <2 types of drugs.

The main guidelines that will be used as a guide in

assessing drug interactions are Drugs.com. In

bivariate analysis using the Chi-Square analysis

method with a categorical measurement scale

(Dahlan, 2014).

3 RESULTS AND DISCUSSION

The sociodemographic characteristic on Ambulatory

Patients with Hypertension of a Secondary Care

Hospital in Bandar Lampung on January – June 2023

was showed in table 1. Hypertensive patients at a

secondary care hospital in Bandar Lampung tends to

be more common in women, namely 78 (57.78%)

patients compared to male patients, namely 57

(42.22%) patients. In the age category, the highest

number of hypertension cases was in individuals aged

≥59 years with 58 (42.96%) patients followed by the

>45-59 years age category with 54 (40%) patients

while the lowest number of cases was recorded in the

age 19-45 years with 23 (17.04%.) patients. There

were 79 (58.52%) prescriptions that used 2-4 drugs

and there were 56 (41.48%) prescriptions that used ≥5

drugs. Patients involved in this study had

comorbidities, with 108 (80%) patients.

Table 1. Sociodemographic characteristics on Ambulatory

Patients with Hypertension of a Secondary Care Hospital in

Bandar Lampung on January – June 2023

Variable Fre

uenc

Percenta

Gender

Male

Female

42.22%

57.78%

Age

19 – 45 years

> 45 - 59 years

> 59

ears

17.04%

40.00%

42.96%

Number of Medications

2 – 4 drugs

> 4 dru

58.52%

41.48%

Commorbid condition

Present

Absent

108

80%

20%

Potential Drug-drug

Interaction

Present

Absent

66.67%

33.33%

Based on table 1, it is explained that the drug-drug

interactions from 135 samples contained 90 (66.67%)

cases with potential drug interactions and 45

(33.33%) cases without potential drug interactions.

Patients suffering from hypertension have a high risk

of experiencing drug interactions due to long-term

treatment and are often given combination therapy.

Table 2: Severity Levels of Potential Drug-drug

Interactions on Ambulatory Patients with Hypertension of

a Secondary Care Hospital in Bandar Lampung on January

– June 2023

Level of

Interaction

Number of Potential

Interactions

Percentage

(%)

Majo

19 6,89%

Moderate 199 72,10%

Mino

58 21,01%

Total 276 100 %

Table 2 shows the results of the evaluation of

potential drug-drug interactions of moderate severity.

It was found that these interactions were the most

common. At major severity levels, the potential drugs

found are combinations that all involve

antihypertensive drugs. The most potential drug-drug

interactions that occur in the combination of

amlodipine and simvastatin are 15 potential

interactions. For major interactions between

amlodipine and simvastatin it can cause a potential

increase in the risk of myopathy (Baxter, 2010).

Amlodipine may significantly increase plasma

concentrations of simvastatin and its active

metabolite and increase the risk of statin-induced

myopathy (Baxter, 2010).

ICOMESH 2023 - INTERNATIONAL CONFERENCE ON MEDICAL SCIENCE AND HEALTH

Then the most moderate interactions occur when

using amlodipine together with bisoprolol. The use of

amlodipine and bisoprolol together has a potential

interaction mechanism. Amlodipine can inhibit the

oxidative metabolism of beta blockers and additive

pharmacological effects by reducing blood pressure

and heart rate (Pikir, 2015). This is in accordance with

research at RSUP Haji Adam Malik Medan which

states that the highest interaction based on severity

level is moderate at 69.8% (Dasopang, 2015).

There are 58 (21,01%) potential minor

interactions. An example of a minor interaction

between amlodipine and lisinopril may have additive

hypotensive effects. Although these drugs are often

safe to use together, careful monitoring of systemic

blood pressure is recommended during

coadministration, especially during the first one to

three weeks of therapy (Triyanto, 2014).

Awareness and understanding of potential drug

interactions needs to be the main focus for doctors

and pharmacists. Regular monitoring by assessing the

patient's clinical signs and, if possible, checking for

drugs in the blood. This action is very important to

reduce the risk of possible drug interactions that may

arise.

Based on the bivariate analysis test between age

of patient and potential drug-drug interactions carried

out using chi-square test, p-value of 0.008 was

obtained. The same thing was shown in research by

Khairiyah et al. (2022) who stated that interactions

commonly occur in geriatric patients, especially

pharmacodynamic interactions caused by additive or

synergistic interactions. Therefore, it can be

concluded that there is a relationship between age of

patient and potential drug-drug interactions in

hypertensive patients at a secondary care hospital in

Bandar Lampung on 2023.

Table 3. Associated Factors of Potential Drug-drug

Interactions on Ambulatory Patients with Hypertension of

a Secondary Care Hospital in Bandar Lampung on January

– June 2023

Factor

Potential Drug-drug

Interaction

value

Yes No

Age

19 – 45 years

> 45 - 59 years

> 59 years

9 (6.67%)

38 (28.15%)

43 (31.85%)

14 (10.37%)

16 (11.85%)

15 (11.11%)

0,008

Number of

medications

2 – 4 drugs

> 4 drugs

44 (32.59%)

46 (34.07%)

34 (25.19%)

11 (8.15%)

0,003

Comorbid

condition

Present

Absent

75 (55.55%)

15 (11.11%)

33 (24.44%)

12 (8.88%)

0,171

The results of the analysis of the relationship

between the number of medications and the potential

drug-drug interactions carried out using chi-square

test showed p-value of 0.003, so it can be concluded

that there is a significant relationship between the

number of medication and the potential drug-drug

interactions. In research conducted by Parulian et al.

(2019), the number of medications that had a

relationship with the number of interactions obtained

a positive correlation (very strong correlation),

namely the greater the number of drugs, the more

interactions that occurred.

Then the results of the analysis of the relationship

between comorbid condition and potential drug-drug

interactions using the chi-square test obtained p-value

of 0.171, so it can be concluded that there is no

significant relationship between comorbid condition

and potential drug interactions. In contrast to previous

research at RSU X in Makassar City, it showed a

significant influence on potential drug-drug

interactions. These results indicate that the number of

medications prescribed is the factor that has the

greatest influence on the potential for drug

interactions.

4 CONCLUSION

The results of the evaluation of potential drug

interactions on 135 prescriptions assessed using tools,

namely drugs.com, showed that in patients receiving

antihypertensive drugs, there were 90 prescriptions

that experienced potential drug interactions, which

were divided into three based on the level of severity,

namely 19 potential major level interactions (6.88% )

interaction potential, moderate level interaction

potential is 199 (72.10%) interaction potential, minor

level interaction potential is 58 (21.01%) interaction

potential.

There is a relationship between the number of

medications and age of patient on potential drug-drug

interactions in hypertensive patients, but there is no

relationship between comorbid condition and

potential drug-drug interactions in hypertensive

patients. The variable most related to potential drug-

drug interactions on ambulatory patients with

hypertension of a secondary care hospital in Bandar

Lampung on January – June 2023 is the number of

medications with p-value of 0.003.

Potential Drug-Drug Interactions and Associated Factors on Ambulatory Patients with Hypertension of a Secondary Care Hospital in Bandar

Lampung

REFERENCES

Baxter, K., & Stockley, I. (2010). Stockley ’s Drug

Interactions Ninth edition. In Pharmaceutical Press

(Ninth Edit). Pharmaceutical Press.

Chalik, R., Karim, D., Dewi, S. T. R., & Hidayati, H.

(2021). Analisis Faktor Yang Berpengaruh Terhadap

Kejadian Interaksi Obat Pada Pasien Hipertensi Di

Rumah Sakit Umum X Kota Makassar. Media Farmasi,

17(1), 55.

Dahlan, S. (2014). Statistik untuk Kedokteran dan

Kesehatan Seri 1 Edisi 6 (Ed.6). Jakarta: Salemba

Medika.

Dasopang, E., Harahap, U., & Lindarto, D. (2015).

Polipharmacy and Drug Interactions in Elderly Patients

with Metabolic Diseases. Indonesian Journal of Clinical

Pharmacy, 4(4), 235–241.

Hastuti, A. P. (2020). Hipertensi. Jateng: Lakeisha.

Khairiyah, U., Yuswar, M. A., & Purwanti, N. U. (2022).

Pola Penggunaan Obat Antihipertensi Pada Pasien

Hipertensi Di Instalasi Rawat Jalan Rumah Sakit. Jurnal

Syifa Sciences And Clinical Reasearch (JSSCR), 4,

609–617.

Mahamudu, Y. S., Citraningtyas, G., & Rotinsulu, H.

(2017). Kajian Potensi Interaksi Obat Antihipertensi

Pada Pasien Hipertensi Primer Di Instalasi Rawat Jalan

Rsud Luwuk Periode January – Maret 2016. Jurnal

Ilmiah Farmasi, 6(3), 1–9.

Parulian, L. (2019). Indonesian Journal of Pharmacy and

Natural Product. Indonesian Journal of Pharmacy and

Natural Product, 02(July), 4–7.

PERHI, K. (2021). Konsensus Penatalaksanaan Hipertensi:

Update Konsensus PERHI 2019. I-Hefcard.Com, 118.

Pikir, B. S., Aminuddin, M., Subagjo, A., Darmadati, B. B.,

Suryawan, I. G. R., & P, J. N. E. (2015). Hipertensi

Menejemen Komprehensif. Surabaya: Airlangga

University Press.

Setyoningsih, H., & Zaini, F. (2022). Hubungan Interaksi

Obat Terhadap Efektivitas Obat Antihipertensi Di Rsud

Dr. R. Soetrasno Rembang. Cendekia Journal Of

Pharmacy, 6(1), 76–88.

Triyanto, E. (2014). Pelayanan Keperawatan bagi Penderita

Hipertensi secara terpadu. Yogyakarta: Graha Ilmu.

Well, B. G., Dipiro, J., Schwinghammer, T. L., & DiPiro,

C. V. (2015). Pharmacotherapy Handbook (Ninth Edit).

MC Graw Hill Education.

Whittlesea, C., & Hodson, K. (2019). Clinical Pharmacy

and Therapeutic (Sixth Edit). Elsevier.

ICOMESH 2023 - INTERNATIONAL CONFERENCE ON MEDICAL SCIENCE AND HEALTH