Age-Related Prescribing Patterns of Antihypertensive Medications

Introduction: Hypertension is the most common modifiable risk factor for cardiovascular diseases, renal failure, and stroke. Previous studies showed that prescription patterns of antihypertensive drugs varied by gender. Aim: This is a retrospective study that was conducted to describe the difference in prescribing antihypertensive drugs according to patients’ age. Methodology: In this study, the electronic prescriptions of hypertensive patients that were dispensed from the outpatient pharmacy of a public hospital in Alkharj were revised. Results: Generally, older patients are using antihypertensive drugs more than younger adults and their usage pattern of antihypertensive drugs is different according to age. Conclusion: It is important to know the age-related prescribing patterns of antihypertensive drugs and to know the efficacy and safety of these agents in different patients in order to develop an evidence-based and age-appropriate antihypertensive pharmacotherapy. Original Research Article Ahmed et al.; JPRI, 32(30): 80-85, 2020; Article no.JPRI.62506 81


INTRODUCTION
Hypertension is the most common modifiable risk factor for cardiovascular diseases, renal failure, and stroke [1]. Clinical evidence suggests that lowering blood pressure with antihypertensive medications decreases the risk of stroke, endstage renal diseases, heart failure, revascularization procedures, and myocardial infarction in hypertensive patients [2].
The increasing prevalence of hypertension has been attributed to population growth, behavioral risk factors (such as unhealthy diet, excess use of alcohol, sedentary lifestyle, and obesity), exposure to persistent stress, and aging [3]. Around 9.4 million deaths occur globally every year because of hypertension [3], with it being responsible for approximately 50% of deaths due to heart disease and stroke [4].
There are several pharmacological classes of antihypertensive drugs that are used to treat hypertension including beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, diuretics, centrally acting agents, renin inhibitors, alphaadrenergic receptor blockers, direct-acting vasodilators, and calcium channel blockers [5].
Previous studies have identified increased use of antihypertensive drugs to coincide with increased control over blood pressure both in older and younger populations and also with decreased cardiovascular mortality, myocardial infarction, and stroke rates [6][7][8].
Advancing age is characterized by impairment of numerous regulatory processes that provide functional integration between cells and organs. Moreover, numerous pharmacokinetic and pharmacodynamic changes occur with advancing age [9]. The pharmacokinetic changes include an increase in the volume of distribution of lipidsoluble drugs and as a result this leads to the prolongation of elimination half-life [9]. Moreover, pharmacokinetic changes include a reduction in renal and hepatic clearance [9]. The pharmacodynamic changes involve altered sensitivity to many classes of drugs such as cardiovascular drugs [9].
Al Khaja et al reported that significant age-and gender-related differences in prescribing patterns were seen at a primary health care centers in Bahrain [10]. Gu et al. reported that there were differences in antihypertensive drug use patterns between older and younger patient groups [11]. Additionally, a previous study reported that prescription patterns varied by gender, clinical facilities, and age [12]. Therefore, this study aimed to describe the difference in antihypertensive medications prescribing patterns according to age.

METHODOLOGY
This is a retrospective study that was conducted to describe the patterns in prescribing antihypertensive drugs according to patients' age. In this study, the electronic prescriptions of hypertensive patients that were dispensed from the outpatient pharmacy of a King Khalid Hospital in Al-Kharj were reviewed.
Inclusion criteria included all hypertensive prescriptions for patients diagnosed with hypertension from January to December 2018 and dispensed by outpatient pharmacy. Prescriptions of patients who had other diseases and didn't have hypertension were excluded. Moreover, the prescriptions that were dispensed by other setting such as inpatient were excluded.
Excel software was used to analyze the data and after that, the data were represented as frequencies and percentages.
The data in the present study included the age of patients, the prescribed antihypertensive classes, and the difference of prescribing antihypertensive drugs according to age.

RESULTS AND DISCUSSION
Among the 1838 patients receiving antihypertensive medications, the age of the majority of these patients was more than 49 years old (71.70%) ( Table 1).
Borzecki et al. reported that patients more than 50 years accounted for 90.7% of hypertensive patients [13]. Similarly, Gu et al. reported that the percentage of hypertensive patients aged 50 to 59 years was high and that the average age of the hypertensive populations were 59.6 years [14].
In contrast to the results of the present study, Kim et al reported that Angiotensin receptors blockers were the most frequently prescribed drug (51.6%) [15]. Liu and Wang reported that calcium channel blockers and beta-blockers were the most frequently prescribed antihypertensive drugs [12]. Wallenius et al. reported that prescribing diuretics and beta blocking agents depended on the patient's age but ACE inhibitors and calcium channel blockers were prescribed with no relation to age. Furthermore, Wallenius et al. reported that the prescribing of diuretics increased with age and that the use of betablocking agents increased until 65 years and then decreased [16].
Patients more than 39 years old used mainly CCBs; more than 89% of patients more than 39 years old use one of the CCBs medications. Regarding diuretics, more than 80% of the patients were more than 49 years old used (Table 3).
In the present study adult, less than 30 years use BBs mainly. Kim et al. reported that patients who are less than 20 years of age use ACEIs and BBs more frequently [15]. In contrast to the present study, Pittrow et al. reported that ACEIs were the most prescribed antihypertensive class for the patient more than 60 years of age and that beta-blockers were the most prescribed for patients less than 60 years of age [17]. Liu and Wang stated that patients aged over 55 years were treated with CCBs more often than younger patients, with beta-blockers, ACE inhibitors, and ARBs being more frequently prescribed among younger patients [12].
The most commonly prescribed antihypertensive drug was amlodipine (25.30%) followed by bisoprolol (13.98%) ( Table 4). Antihypertensive drugs were prescribed mainly for patients more than 39 years old; for example, 90.53% of amlodipine prescriptions and 90.66% of bisoprolol prescriptions were for patients more than 39 years old (Table 5).
In the present study, amlodipine was the most prescribed calcium channel blockers, bisoprolol was the most commonly prescribed betablockers, furosemide was the most commonly prescribed diuretics, Lisinopril was the most commonly prescribed ACE inhibitors and valsartan was the most commonly prescribed Angiotensin receptors blockers.   Gu et al. stated that diuretics (predominantly thiazide diuretics) were the most commonly prescribed antihypertensive drug class and that beta-blockers and angiotensin receptor blocker were among the most commonly prescribed antihypertensive agents [11]. In contradiction to the present results, Al Khaja et al. reported that beta-blockers were the most frequently prescribed antihypertensive and that atenolol was mainly used, for diuretics indapamide was mainly used, for ACE inhibitors captopril was mainly used and for calcium channel blockers nifedipine was mainly used [10].

CONCLUSION
It can be concluded that older patients are using antihypertensive drugs more than younger adults and that there is a difference in usage pattern of antihypertensive drugs according to age.

CONSENT
It is not applicable.

ETHICAL APPROVAL
This study was approved by the IRB ethical committees with IRB log No: 2019-0153E.

ACKNOWLEDGEMENT
"This Publication was supported by the Deanship of Scientific Research at Prince Sattam bin Abdulaziz University"