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Submitted: 08 September 2020 | Approved: 30 September 2020 | Published: 01 October 2020

How to cite this article: Ukoha-Kalu BO, Adibe MO, Ukwe CV. Identification and resolution of drug therapy problems among hypertensive patients receiving care in a Nigerian - A pilot study. Ann Clin Hypertens. 2020; 4: 020-023.

DOI: 10.29328/journal.ach.1001024

Copyright: © 2020 Ukoha-Kalu BO, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Identification and resolution of drug therapy problems among hypertensive patients receiving care in a Nigerian - A pilot study

Blessing Onyinye Ukoha-kalu*, Maxwell Ogochukwu Adibe and Chinwe Victoria Ukwe

Department of Clinical Pharmacy and Pharmacy Management, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, Enugu state, Nigeria

*Address for Correspondence: Blessing Onyinye Ukoha-Kalu, Department of Clinical Pharmacy and Pharmacy Management, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, Enugu State, Nigeria, Tel: +2347031997902; Email: blessing.ukoha-kalu@unn.edu.ng

Background: An event involving drug therapy that actually or potentially interfers with the desired health outcomes is known as drug therapy problem.

Objective: The study aimed to identify and resolve potential drug related problems encountered among adult hypertensive patients receiving care in a Nigerian Tertiary Hospital. Methods: This was a prospective cross sectional study. The data were collected from the patients’ medical records using the Pharmaceutical Care Network Europe (PCNE) Classification tool Version 6.2 (PCNE, 2010). For each of the 171 medical records, the DTPs experienced within the study period were identified. Data were analyzed using the IBM Statistical Product and Service Solutions (SPSS) for Windows, Version 21.0 (IBM Corp, Version 21.0, and Armonk, NY, USA).

Results: Majority of the patients were above 65years of age 64(37.4%), while about half of the patients were females. A total of 644 drug therapy problems were identified. The major cause of DTP was prescribing error 189(29.3). Other causes of drug therapy problem identified in this study were inappropriate drug selection 122(18.9), no indication for drugs 52(8.1), inappropriate drug combination 87(13.6), new indication presented 61(9.5), dose too high 62(9.6), dose too low 44(6.8), wrong drug taken/administered 27(4.2). Majority of the interventions made were accepted 586(91.0%) while only 3(0.5%) of the interventions made were not accepted.

Conclusion: This study demonstrates that a pharmacist, with adequate training and support can play a vital role in identifying and resolving drug therapy problems. Also, there is a need for an educational intervention among prescribing physicians to update them regularly on hypertension guidelines.

An event involving drug therapy that actually or potentially interferes with the desired health outcomes is known as drug therapy problem [1]. Drug therpy problems is defined by the World Health Organization (WHO) as “any response to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function” [2]. Hypertension is the most common cardiovascular disease. In a surveyed carried out in 2009, hypertension was in 28% of American adults and 60% of adults 65 years or older [1]. The prevalence varies with age, race and education. According to some studies, 60% - 80% of both men and women will develop hypertension by age of 80 [3]. Analysis of the global burden of hypertension revealed that over 26% of the world’s adult population had hypertension in 2000, and has shown a rapid increase in prevalence affecting significant numbers of individuals in Sub-Saharan Africa [4].

Studies worldwide indicate that despite the availability of effective medical therapy, more than half of hypertensive patients on treatment have blood pressures over 140/90 mm Hg threshold [5]. This is mostly because of drug therapy problems which include but not limited to non-compliance, ADRs, improper drug selection and drug interactions.

The occurrence of a DTP among hypertensive patients could prevent or delay patients from achieving desired therapeutic goals [6]. It has been attributed to unnecessary over-prescription of drugs, substantial worsening of diseases, avoidable increases in hospital admission rates, and longer hospital stays leading to a significant medical burden [7]. As a result, substantial numbers of patients do not get the maximum benefit of medical treatment, resulting in poor health outcomes, lower quality of life, increased health care costs and erodes public confidence in health systems [8].

Objective

This study aimed to assess the Knowledge, attitude and practice towards hypertension among hypertensive patients receiving care in a Nigerian hospital.

Study design: This was a prospective study which involved the medical records of Adult hypertensive patients receiving care in a tertiary hospital in Kogi state, Nigeria.

Ethical committee approval: Ethical approval was obtained from the Health Research and Ethics Board of the Kogi State Specialist Hospital, Ministry of Health Kogi State before commencement of the study.

Eligibility criteria: The eligibility criteria included all the folders of hypertensive with Diabetes comorbidity outpatients who received prescription from the hospital within the study period (August-September 2019).

Sample size calculation: All folders that fell within the eligibility criteria were utilized for the study. A total of 171 patient folders were used.

Data collection

The data were collected from the patients’ medical records using the Pharmaceutical Care Network Europe (PCNE) Classification tool Version 6.2 (PCNE, 2010). For each of the 171 medical records, the DTPs experienced within the study period were identified. The demographic information such as age and gender were recorded. Other items documented were the drugs implicated in the therapy problems, type of drug therapy problem, cause of drug therapy problem (DTP), type of intervention and the outcome of intervention. The PCNE V 6.2 has 4 primary domains for problems, 8 primary domains for causes and 5 primary domains for interventions. On a more detailed level, there are 9 grouped sub-domains for problems, 37 grouped sub-domains for causes and 17 grouped sub-domains for interventions. The sub-domains are explanatory for the principal domains.

Data analysis

Data were analyzed using the IBM Statistical Product and Service Solutions (SPSS) for Windows, Version 21.0 (IBM Corp, Version 21.0, and Armonk, NY, USA).

Majority of the patients were above 65years of age 64(37.4%), while about half of the patients were females. Also, most of the patients were traders 62(36.3%), 146(85.4%) were married, 146(79.1%) were Christians by religion and 164(95.9%) were currently non-smokers as at the time of the study (Table 1).

Table 1: Demographic characteristics of patients.
Characteristics Frequency Percentage
Age    
18-25 1 0.6
26-35 7 4.1
36-45 19 11.1
46-55 28 16.4
56-65 52 30.4
> 65 64 37.4
Gender    
Male 84 49.1
Female 87 50.9
Employment status    
Civil servants 21 12.3
Trader 62 36.3
Famer 44 25.7
Unemployed 8 4.7
Retired 20 11.7
Self employed 16 9.4
Marital status    
Single 10 5.8
Married 146 85.4
Separated 0 0
Divorced 0 0
Widowed 15 8.8
Religion    
Christian 166 97.1
Muslim 1 0.6
Pegan 4 2.3
Smoking status    
Current smoker 4 4.1
Non-current smoker 164 95.9

A total of 644 drug therapy problems were identified. Some of the drugs involved in DTP were, methyl dopa, frusemide, Nifedipine, lisinoril, metformin, metronidazole, analgesics like diclofenac, ibuprofen and paracetamol (Table 2).

Table 2: Drugs Involved With Identified Drug Therapy Problems.
Name of medication Drug therapy problem n (%)
Methyldopa + frusemide Enhanced hypotensive effect 112(17.4%)
Artesunate + Vitamin C Inhibition of the oxidation of artemisinin derivatives by vitamin C 101(15.7)
Arthemether/Lumefantrine+ Vitamin C Inhibition of the oxidation of artemisinin derivatives by vitamin C 92(14.3)
Aspirin 75mg No direction for use 84(13.0)
Nifedipine Dose too high 59(9.2)
Lisinopril No direction for use 58(9.0)
Methyldopa No direction for use 55(8.5)
Metformin Dosage too low 22(3.4)
Artesunate No direction for use 15(2.3)
Metronidazole No indication for drug 14(2.2)
Diclofenac+ Ibuprofen Wrong drug combination 11(1.7)
Artesunate Dosage too low 9(1.4)
Artemether/Lumefantrine Dosage too low 7(1.1)
Others   5(0.8)
*Others: spirinolactone, valsartan, hydrochlorothiazide, paracetamol, loperamide.

The major cause of DTP was prescribing error 189(29.3). Other causes of drug therapy problem identified in this study were inappropriate drug selection 122(18.9), no indication for drugs 52(8.1), inappropriate drug combination 87(13.6), new indication presented 61(9.5), drug too high 62(9.6), drug too low 44(6.8), wrong drug taken/administered 27(4.2) (Table 3).

Table 3: Causes of Drug therapy Problem.
Variables n (%)
Drug selection
Inappropriate drug
No indication for drug
Inappropriate drug combination
New indication presented
122(18.9)
52(8.1)
87(13.6)
61(9.5)
Dose selection
Drug too high
Drug too low
62(9.6)
44(6.8)
Drug use process
Wrong drug taken/administered
Prescribing error
27(4.2)
189(29.3)

Majority of interventions made were on drug level 288(44.7%), while 183(28.4%) were made on patient level. Also, 152(23.6%) of the interventions were made on prescriber level while 21(3.3%) of the DTPs had no intervention (Table 4).

Table 4: Types of intervention.
Variable n (%)
No intervention 21(3.3)
Prescriber level 152(23.6)
Drug level 288(44.7)
Patient level 183(28.4)

Majority of the interventions made were accepted 586(91.0%) while only 3(0.5%) of the interventions made were not accepted (Table 5).

Table 5: Outcome of intervention.
Variable n (%)
Intervention accepted 586(91.0)
Intervention not accepted 3(0.5)
Outcome unknown 55(8.5)

Various drug combinations were responsible for the DTPs which may have resulted to therapy failure or adverse drug reactions. The use of methyldopa with frusemide constituted the major drug therapy problems in this study. Majority of the identified DTPs were due to adverse reactions. Most of the respondents were above 65 years of age, female and taking more than two medications. This is supported by the findings that adverse drug reactions occur mainly in young and middle aged adults and are twice as common in women [10]. From this study, patients who were on more than one medication experiences DTP more than those that were on a single medication. The use of multiple medications predisposes patients to adverse drug reactions [11]. Most of the patients in this study were on more than three drugs. Some of these medications may also predispose the patients to other disease states as a study showed that the long duration of therapy with beta-2 agonists positively correlated with the incidence of hypertension [12]. Our findings establish that prescribing error and inappropriate drug combinations were the major cause of drug therapy problems. This contrasts the results obtained in a recent study on drug therapy problems in adult hypertensive patients where about 40% of the drug therapy problems were due to non-adherence to medication (66%) [13]. Several studies have shown that most DTPs (48.75%) were from potential drug interactions [14]. Pharmacists can help in the making the right choice of drugs and possible combinations. Also, counselling can improve patient adherence and the outcome of therapy [14]. Inappropriate drug selection may be due to inappropriate prescribing. Less than a quarter of the DTPs had no documented interventions which might have stemmed from poor attitudes to documentation and poor patient-care approach. From the interventions documented, more than three-quarter had known intervention outcomes. Poor drug history documentation may lead to medication errors [15]. Health professionals should document appropriately to minimize or eliminate medication errors. Pharmacists’ participation in medication history documentation might significantly increase the frequency and depth of medication history information documented [15].

This study demonstrates that a pharmacist, with adequate training and support can play a vital role in identifying and resolving drug therapy problems in the hospital. Also, there is a need for an educational intervention among prescribing physicians to always keep them abreast with the current hypertension guidelines.

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