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 Table of Contents  
ORIGINAL RESEARCH REPORT
Year : 2018  |  Volume : 15  |  Issue : 4  |  Page : 186-193

Economic burden, impact, and consequence of adverse drug reactions among medical inpatients in clinical practice


1 Department of Internal Medicine, Irruar Specialist Teaching Hospital, Irruar, Edo State, Nigeria
2 Department of Pharmacology and Therapeutics, Faculty of Basic Clinical Sciences, University of Medical Sciences, Ondo City, Ondo State, Nigeria
3 Department of Internal Medicine, University of Benin Teaching Hospital, Benin City, Edo State, Nigeria, Benin City

Date of Web Publication3-Dec-2018

Correspondence Address:
Dr. Olumuyiwa John Fasipe
Department of Pharmacology and Therapeutics, Faculty of Basic Clinical Sciences, University of Medical Sciences, Ondo City, Ondo State
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jcls.jcls_64_18

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  Abstract 


Background: An adverse drug reaction (ADR) is defined in this study as a response to a drug which is noxious and unintended that occurs at doses normally used for therapeutic purposes. Despite the extensive study and attention given to ADRs, they still represent a clinically significant problem and burden with high prevalence. Aim: The main aim of this study was to adequately evaluate the economic burden, impact, and consequence of ADRs among adult medical inpatients in clinical practice, to highlight the pattern of medications most frequently involved in ADRs, and to estimate the economic cost implication of treating ADRs in such clinical practice setting. Methods: The patients admitted into the adult medical wards of a Nigerian university teaching hospital over a 9-month period from December 2013 to August 2014 were prospectively recruited for the study and followed up till discharge. Results: Five hundred and seven patients were evaluated during the study, out of which 269 (53.1%) of them were male and 238 (46.9%) were female. The mean age of the study population was 48.9 ± 17.8 years (median: 46 years). Most ADRs were mild and moderate in 21 (41.2%) cases and 24 (47.1%) cases, respectively. Severe ADRs occurred in 2 (3.9%) cases, while four (7.8%) cases were fatal ADRs. The economic cost implication of treating ADRs was ₦ 161,668.00 ($1243.60), equivalent to about 1.9% of the total cost of all medications used by all admitted medical inpatients during admission. The cost of treating ADRs per patient with ADRs was ₦ 3169.96 ± ₦ 6348.77 ($24.38 ± $48.84), while the mean ADR treatment cost per admitted medical inpatient was ₦ 318.87 ($2.45). The most frequently affected body systems by ADRs were the central nervous system and the gastrointestinal system corresponding to the antidiabetic drug – insulin use causing neuroglycopenic symptoms and nonsteroidal anti-inflammatory drugs (NSAIDs) use causing NSAID-induced gastroenteritis/GIT bleeding, respectively. Conclusions: The economic burden, impact, and consequence of ADRs were significantly high among these adult medical inpatients. In this study, ADRs increase patients' morbidity, mortality, cost of health care, and length (duration) of hospitalization. Insulin and NSAIDs caused the highest number of ADRs which indicate that adequate caution, proper care, and continuous monitoring must be implemented during the course of treating patients with these drugs to optimize their clinical efficacy and prevent the occurrence of ADRs in them.

Keywords: Adverse drug reaction, consequence, economic burden, impact, insulin, medical inpatients, nonsteroidal anti-inflammatory drugs


How to cite this article:
Akhideno PE, Fasipe OJ, Isah AO, Owhin OS. Economic burden, impact, and consequence of adverse drug reactions among medical inpatients in clinical practice. J Clin Sci 2018;15:186-93

How to cite this URL:
Akhideno PE, Fasipe OJ, Isah AO, Owhin OS. Economic burden, impact, and consequence of adverse drug reactions among medical inpatients in clinical practice. J Clin Sci [serial online] 2018 [cited 2018 Dec 15];15:186-93. Available from: http://www.jcsjournal.org/text.asp?2018/15/4/186/246769




  Introduction Top


Medications are essentially important in the clinical practice of patient care by well-trained health-care professionals. Patient management often requires the use of medications. The use of medicines for patient care is considered to be a major component of patient management in health-care settings.[1],[2],[3] Pharmacological interventions sometimes carry inherent significant risks which include adverse drug reactions (ADRs), drug interactions, and other consequences of inappropriate medication use.[4],[5],[6],[7] An ADR is defined in this study as a response to a drug which is noxious and unintended that occurs at doses normally used for therapeutic purposes.[8],[9],[10] ADRs have been known to cause significant morbidity and mortality for centuries being as old as medicine itself.[11],[12],[13],[14]

Despite the extensive study and attention given to ADRs, they still represent a clinically significant problem and burden with high prevalence.[15],[16],[17],[18] In the United States, for example, pharmaceutical treatment results sometimes in adverse drug events either due to inherent ADRs or from inappropriate medicine use or medication errors. These were noted in over 1.2 million hospital stays or about 3.1% of all hospital stays in the US in 2004.[19],[20],[21] The incidence of serious and fatal ADRs in the US hospitals was noted to be extremely high at 6.7% and 0.32%, respectively, making these reactions between the fourth and sixth leading causes of death.[22],[23],[24]

In the United Kingdom (UK), the incidence of ADRs among admitted patients was found to be 6.5% and admissions related to ADRs cost the national health scheme (NHS) up to £466 million annually or 0.62% of annual health budget.[25],[26],[27],[28] Furthermore, at a particular time in the UK, the equivalent of up to seven 800-bed space hospitals was occupied by patients with ADRs, which amounts to about 4% of hospital bed capacity in the UK. The duration of hospital stay was also increased by ADRs. The foregoing underscores the importance of the economic burden posed by ADRs.[29],[30],[31],[32]

In developing countries including Nigeria, there is minimal information on the inhospital incidence of ADRs, the culprit medications, and the economic cost implication of management.[33],[34],[35] This information is useful for health planning, management, budgeting, policy formulation, and development of treatment protocols to enable appropriate and optimal patient care.[36],[37],[38]

This study was therefore designed to evaluate the economic burden, impact, and consequence of ADRs among adult medical inpatients at the University of Benin Teaching Hospital (UBTH), Benin City, Edo State, Nigeria, to highlight the pattern of medications most commonly involved, and to estimate the economic cost implication of treating ADRs in such clinical practice setting.


  Methods Top


This was a descriptive, prospective study with serial entry points for the patients admitted into the internal medicine wards of UBTH, Benin City, Edo State, South-South Nigeria, over a 9-month period from December 2013 to August 2014. They were all adult medical patients whose ages were above 17 years and were fulfilling the inclusion criteria for recruitment and evaluation and followed up. Medications prescribed for the admitted patients were supplied by the hospital pharmacy, or however, they may occasionally be required to purchase some medications from retail outlets outside the hospital when these drugs are not available in hospital pharmacy. Patients are generally admitted through the accident and emergency unit where they are reviewed by various cadres of medical doctors until they are transferred to the wards under unit consultants. Some patients are admitted directly from the outpatient clinics into the wards, while a few may be transferred from other nonmedical wards. The patients are then reviewed daily in the various units and managed till discharge.

The inclusion criteria for evaluation were all the patients admitted to the medical wards after commencing the study provided they granted their informed consents to participate in the study.

The exclusion criteria were as follows:

  1. Patients already on admission before commencing the study
  2. Patients admitted from other wards after initial management for nonmedical condition(s)
  3. Patients diagnosed and subsequently managed for nonmedical condition(s) after initial medical diagnosis and management
  4. Patients who did not grant their informed consents to participate in the study.


Data information about all the recruited patients were obtained and entered into a data collection form modified from the WHO-International Network of Rational Use of Drugs prescribing indicator form.[3] Patients were evaluated with respect to medications used on days 0 (admission day), 1, 3, 7, 10, 14, 21, and weekly thereafter till the day of discharge or death. An encounter was regarded as a patient studied on admission on such specified days. An initial sociodemographic data stating age, sex, religion, and occupation among others were obtained at admission. Thereafter, the records of all prescribed medications including the dates, route, doses, and frequencies were all noted for these inpatients during admission. The reviews and changes made in patients' medications between the days of evaluation were also noted to enable the estimation of number of drugs taken during admission and their costs.

Information concerning ADR occurrence and its nature was sought from attending physicians, patients, their relatives, and nursing staff. Charts and case notes were screened for records of ADRs. Clinical evaluation and assessment of laboratory results were also carried out. Repeated admission of the same patient was regarded as two separate admissions when separated by an interval of at least 1 month, otherwise such admission was considered as a single admission and the interval excluded from the duration of hospital stay.[16]

The cost of medicines was estimated from unit cost of medicines obtained from the hospital pharmacy price list. The cost of the occasional medicine not available in hospital pharmacy was also estimated using the same price list for uniformity as well because the cost difference was not often remarkable.

The definition of ADRs used in the study was that of the WHO: any noxious and unintended response to a drug that occurs at doses used in humans for the prophylaxis, diagnosis, or therapy of disease.[3] ADRs were classified as mild (laboratory abnormality or symptoms not requiring treatment), moderate (laboratory abnormality or symptoms requiring treatment /admission to hospital or resulting in non-permanent disability), severe (laboratory abnormality or symptoms that were life threatening or resulted in permanent disability), and fatal (any ADR that resulted in patient's death regardless and irrespective of the initial severity grading assessment).[13],[14] Causality of ADR was assessed using the WHO causality criteria[15] as well as the Naranjo algorithm,[16] while the ADRs were classified according to the System/Organ Class.[11]

Data collected were encoded and analyzed using the Statistical Package for the Social Sciences (SPSS) version 17 (released 2008; SPSS Incorporations, Chicago, Illinois, United States of America). Results were expressed as mean ± standard deviation or using frequency and percentage values where necessary. The t-test and Chi-square were used to compare means and proportions, respectively. The level of statistical significance was set at P < 0.05.

Ethical clearance was obtained from the UBTH Ethical Research Committee before commencing this study. The ethical clearance/protocol research number issued for the study was ADM/E.22 A/VOL.VII/104. In addition, a verbal informed consent was obtained from each of the patients whose medical records were used, while the medical records for those who did not grant their informed consent were excluded from the study. Consent was sought from patient's relative where a patient had impaired level of consciousness. Participants' confidentiality were respected and maintained by ensuring that no unauthorized person had access to the information on the data information sheets that no information can be traced to the subjects (as coding system was used for the data information sheets instead of writing the patients' names on them) and no unauthorized use of information was made.


  Results Top


A total of 507 admitted patients were evaluated during this study. Regarding sex distribution, 269 (53.1%) were male, while 238 (46.9%) were female. The mean age for all patients was 48.9 ± 17.8 years (median: 46 years; range: 17–89 years). Although the mean age for females (49.5 ± 17.7 years) was older than that of the males (48.3 ± 17.9 years), the difference was not statistically significant (t = −0.771, df = 505, P = 0.44). [Table 1] showed the age and sex distribution of the patients. [Table 1] revealed that those patients under 45 years of age were the most predominant with a frequency of 236 (46.5%) patients, followed by those within the age group of 45–64 years with a frequency of 146 (28.8%) patients, while the elderly age groups (65 years and above) constitute 125 (24.7%) of the admitted patients.
Table 1: Age and sex distribution of medical inpatients evaluated for adverse drug reactions in a Nigerian teaching hospital from December 2013 to August 2014

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[Table 2] showed the details of the medications causing ADRs. The most common drugs causing ADRs in order of frequency were insulin in 14 (27.5%), nonsteroidal anti-inflammatory drugs (NSAIDs) in 10 (19.6%), antihypertensives in 8 (15.7%), and antimalarials in 5 (9.8%). In addition, herbal medicines and antibacterials caused ADRs in 4 (7.8%) and 3 (5.9%) of patients, respectively. The other medications involved in ADRs are shown in [Table 2]. Furthermore, four fatal ADRs were observed during the study, in which herbal medicines caused two deaths, sulfadoxine/pyrimethamine combination (Maloxine®) caused one death, and iron dextran caused one death.
Table 2: Individual medicines causing adverse drug reactions among inpatients in a Nigerian teaching hospital from December 2013 to August 2014

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[Table 3] showed the summary for duration of hospital stay by different categories of patients. The mean duration of stay by all patients was 11.9 ± 11.3 days (median: 9 days). Females had a mean duration stay of 12.9 ± 12.3 days (median: 10 days) and stayed significantly longer than males who stayed a mean duration of 10.9 ± 10.2 days with a median of 7 days (t = −1.985, df = 505, P = 0.048). The young age group (that is those <45 years old) stayed a mean duration of 11.3 ± 9.3 days (median: 9 days), while the middle age group had a mean duration stay of 11.7 ± 9.7 (median: 10 days). While the elderly age group (65 years and above) had a mean duration stay of 13.0 ± 15.7 (median: 8 days) appeared to have stayed longer than patients below 65 years of age (that is, the young and middle age groups). However, this was not found to be statistically significant (t = −1.299, df = 505, P = 0.195).
Table 3: Duration of hospital stay (days) by different categories of inpatients in a Nigerian teaching hospital from December 2013 to August 2014

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Patients admitted solely because of ADRs (ADR-out) had a significantly shorter duration of stay with a mean duration stay of 6.1 ± 3.7 days (median duration stay: 7 days) when compared to those without ADRs whose mean duration of stay was 11.6 ± 11.0 days (median duration stay: 8 days), and this was found to be statistically significant (t = 2.110, df = 472, P = 0.035). Those patients who developed ADRs during admission (ADR-in) had a mean duration of stay of 18.3 ± 14.8 (median: 15 days). This was significantly longer than the duration of stay for patients without ADRs (t = −3.398, df = 487, P = 0.001) and also significantly longer than the duration for those who were admitted solely because of ADRs (t = 3.432, df = 49, P = 0.001).

[Figure 1] showed the frequency distribution pattern for patients experiencing ADRs versus their precipitant culprit drugs. Insulin caused ADRs in most number of patients 14 (27.5%). NSAIDs were next in frequency of causation in 10 (19.6%), followed by antihypertensives in 8 (15.7%). Antimalarials, herbal medicines, and antibacterials caused ADRs in 5 (9.8%), 4 (7.8%), and 3 (5.9%) of patients, respectively. The other medications involved in ADRs are shown in [Figure 1].
Figure 1: Medications causing adverse drug reactions among medical inpatients in a Nigerian teaching hospital from December 2013 to August 2014

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The systems/organs involved in ADRs are showed in [Figure 2]. The most frequently involved body system was the central nervous system (neurological) in 169 (33.3%) patients. This was followed by the gastrointestinal system in 110 (21.6%) patients, the skin (dermatological) in 89 (17.6%) patients, and cardiovascular system in 40 (7.8%) patients. The endocrine, respiratory, and renal systems were equally affected in 20 (3.9%) patients each. In this study, it was observed that ADRs often affected multiple body systems in a patient.
Figure 2: Organ/system affected by adverse drug reactions among medical inpatients in a Nigerian teaching hospital from December 2013 to August 2014

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The causality rating for the observed ADRs was assessed using both the WHO rating and the Naranjo algorithm as shown in [Table 4]. Using the WHO rating, certain cases were 10 (19.6%), probable cases were 17 (33.3%), and possible cases were 24 (47.1%). Using the Naranjo algorithm, definite cases were 9 (17.6%), probable cases were 19 (37.3%), and possible cases were 23 (45.1%).
Table 4: Causality rating of adverse drug reactions observed among medical inpatients in a Nigerian teaching hospital using the WHO and the Naranjo algorithms from December 2013 to August 2014

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An evaluation of some known risk factors for ADRs considered gender, age, number of medications used, and number of comorbidities. Gender was not found to be a statistically significant risk factor for ADRs in this study (χ2 = 0.371, P = 0.542). Age was found to be a statistically significant risk factor as the elderly age group (age ≥65 years) were more at risk compared to those patients <65 years (Chi-square = 10.152, P = 0.001). The number of medications used was also a significant risk factor for developing ADRs (χ2 = 13.174, P = 0.018). A number of comorbidities were also found to be strongly associated with ADRs (χ2 = 21.962, P < 0.001). This was summarized in [Table 5]. The association of ADRs with the number of medications being used by the patients or the association of ADRs with the number of patients' comorbidities was estimated by excluding patients who were admitted for ADR (that means patients who developed ADRs before admission).
Table 5: Assessment of some known risk factors for adverse drug reactions among medical inpatients in a Nigerian teaching hospital from December 2013 to August 2014

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ADRs were classified as mild (laboratory abnormality or symptoms not requiring treatment), moderate (laboratory abnormality or symptoms requiring treatment /admission to hospital or resulting in non-permanent disability), severe (laboratory abnormality or symptoms that were life threatening or resulted in permanent disability), and fatal (any ADR that resulted in patient's death regardless and irrespective of the initial severity grading assessment).[13],[14] Most ADRs were mild and moderate in 21 (41.2%) cases and 24 (47.1%) cases, respectively. Severe ADRs occurred in two (3.9%) cases, while four (7.8%) cases were fatal ADRs.

[Table 6] showed that the number of patients admitted solely because of ADRs (ADR-out) was 18, which accounts for 3.6% of admissions, while those that experienced ADRs during admission (ADR-in) were 33 (6.5%) patients. The total number of patients who had ADRs was 51, giving an ADR prevalence of 10.1% and incidence of 6.5%. The case fatality rate for ADRs was 7.8% (4/51), while the ADR-related mortality rate was 0.8% (4/507). Furthermore, the percentage of all admitted medical inpatients' medications total cost spent on treating ADRs was 1.9%. The cost of treating ADRs per patient with ADRs was ₦ 3169.96 ± ₦ 6348.77 ($24.38 ± $48.84), while the mean ADR treatment cost per admitted medical inpatient was ₦ 318.87 ($2.45). As of the time this study was being carried out, the currency exchange rate at the international market was $1.00 US dollar equivalent to about ₦ 130.00 Nigerian Naira.
Table 6: Incidence, prevalence, and treatment cost of adverse drug reactions among medical inpatients evaluated for adverse drug reactions in a Nigerian teaching hospital from December 2013 to August 2014

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  Discussion Top


Looking at the available reference literature, this appears to be the first study evaluating the ADR profile and its economic burden, impact, and consequence among adult medical inpatients in a tertiary health-care clinical practice setting in Nigeria. ADRs occurring during admission (incidence) were observed in 6.5% of admitted patients, while 3.6% of the patients were admitted due to an ADR. The prevalence of 10.1% was similar to the ADR prevalence obtained in some European studies ranging from 6.6% to 11%.[6],[11],[17] A meta-analysis in the United States by Lazarou et al. obtained an incidence of 6.7% for serious ADR among inpatients. The incidence and prevalence values observed in this study thus appear to be consistent with values in previous studies done in Switzerland, France, and the UK.[9],[11],[17]

The ADR-related mortality rate of 0.8% was somewhat between values obtained in a UK study (0.15%) and to that obtained in a Swiss study (1.4%). The lower rate observed in the UK study can be attributed to the fact that the study looked at ADRs causing admissions only. The Swiss study showed a higher mortality but also looked at both ADRs causing admission and those occurring during admission.[6],[11]

Patients experiencing ADR during hospitalization (ADR-in) stayed significantly longer than those without ADRs (median stay: 15 vs. 8 days, respectively). ADRs have been found to prolong the duration of hospital stay in several studies.[6],[7],[8],[9] The median length of stay obtained for patients with ADR-in and those without ADR (15 and 8 days, respectively) is similar to results obtained in an inpatient study by Davies et al. (14.5 and 8 days, respectively). Patients admitted solely because of ADRs (ADR-out) had a statistically significant shorter duration of hospital stay (median: 7 days) than those patients without ADR that stayed a median duration of 8 days and also much shorter than those patients that developed ADR during hospitalization (median duration: 15 days). The finding of shorter duration of hospital stay for patients with ADR causing admission (occurring outside the hospital) compared to those without ADR and those with ADR occurring during admission has been noted in a French study. This shorter duration of hospital stay is related to the fact that there is a shorter diagnostic time for ADRs, in effect a shorter time was spent looking for the cause of morbidity since this was obvious from initial clinical evaluation, especially as most of the ADRs were mild (41.2%) or moderate (47.1%). Furthermore, their clinical management was essentially observational care and measures such as stopping or adjusting drug dosage.[17] However, a few of the patients required more intense treatment with prolonged stay.

Gender was not found to be a statistically significant risk factor associated with ADR in this study. This finding here differs from what has been observed in other several studies.[6],[11],[17],[18] The association of gender and ADRs such as other aspects of ADRs is not well characterized among Nigerians and may differ. Some other known risk factors for ADR, however, were found to be significantly associated with ADRs in this study. These were age (elderly), number of prescribed medications (polypharmacy), and number of comorbidities.

The most commonly affected system by ADRs was the central nervous system, probably because two out of the first three topmost implicated classes of medications causing ADRs manifest with symptoms referable to the central nervous system. For example, insulin leads to impair consciousness due to hypoglycemia, while antihypertensives manifest mainly with postural dizziness and headache due to postural hypotension and increased intracranial pressure, respectively. The next most common system involved was the gastrointestinal system, and this may be related to the fact that NSAIDs which constituted the second most common class of medications involved in ADRs usually manifest with problems referable to the gastrointestinal system. In fact, the systems largely affected followed the pattern of medications causing ADRs. Fattinger et al. found the gastrointestinal and the hematological systems as the first and second most commonly affected, respectively, among inpatients. The pattern of morbidity and thus medication used differ in both settings; therefore, the pattern of ADRs will be different.

Mild and moderate ADR cases were far more frequent (41.2% and 47.1%, respectively) when compared to severe and fatal ADR cases. This pattern is similar to findings in other studies.[13],[14]

The two methods used to ascertain causality rate for ADRs caused by a suspected drug, the WHO and Naranjo algorithms, showed similar causality ratings, strengthening the ascribed causality ranking.

The average cost of medications for treating ADRs among inpatients was ₦ 3169.96 ($24.38 or £12). Arulmani et al., in India, obtained an average cost of £6 which was lower. The cost of medications may differ being cheaper in Indian that is a large manufacturer and exporter of drugs to other countries including Nigeria. The percentage cost of all medical inpatients' medications spent on treating ADRs (1.9%) suggests that ADRs cost a lot to the health-care system as shown in previous studies.[6],[17] It is noteworthy that this study considered only the cost of drug therapy. Costs of bed space, investigations, meals, and other miscellaneous costs were not evaluated.


  Conclusion Top


The economic burden, impact, and consequence of ADRs were significantly high among these adult medical inpatients in this Nigerian teaching hospital. In this study, ADRs increase patients morbidity, mortality, cost of health care, and length (duration) of hospitalization. Insulin and NSAIDs caused the highest number of ADRs which indicate that adequate caution, proper care, and continuous monitoring must be implemented during the course of treating patients with these drugs to optimize their clinical efficacy and prevent the occurrence of ADRs in them. This information is useful for health planning, management, budgeting, policy formulation, and development of treatment protocols to enable appropriate and optimal patient care.

Acknowledgments

The authors of this research work want to specially acknowledge and thank the Almighty God for granting us wisdom and understanding to prepare this research work for publication.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Mohamed YH, Mandira D, Fatema M. Drug utilization and antibiotic use in the primary health care centers in Sharjah. East Mediterr Health J 1997;3:444-51.  Back to cited text no. 1
    
2.
Elixhauser A, Owens P. Adverse Drug Events in U.S. Hospitals. Healthcare Cost and Utilization Panel Statistical Report; April, 2007. Available from: www.hcup-us.ahrg.gov. [Last accessed on 2015 Jul 19].  Back to cited text no. 2
    
3.
NAFDAC. Safety of Medicines in Nigeria – A Guide for Detecting and Reporting Adverse Drug Reactions. NAFDAC/NPC/NIG; 2004. p. 1.  Back to cited text no. 3
    
4.
Beard K, Lee A. Introduction to Adverse Drug Reactions. 2nd ed. London: Pharmaceutical Press; 2006. p. 1-3.  Back to cited text no. 4
    
5.
Pirmohamed M, Park BK. Adverse drug reactions: Back to the future. Br J Clin Pharmacol 2003;55:486-92.  Back to cited text no. 5
    
6.
Pirmohamed M, James S, Meakin S, Green C, Scott AK, Walley TJ, et al. Adverse drug reactions as cause of admission to hospital: Prospective analysis of 18 820 patients. BMJ 2004;329:15-9.  Back to cited text no. 6
    
7.
Davies EC, Green CF, Mottram DR, Pirmohamed M. Adverse drug reactions in hospital in-patients: A pilot study. J Clin Pharm Ther 2006;31:335-41.  Back to cited text no. 7
    
8.
Davies EC, Green CF, Taylor S, Williamson PR, Mottram DR, Pirmohamed M, et al. Adverse drug reactions in hospital in-patients: A prospective analysis of 3695 patient-episodes. PLoS One 2009;4:e4439.  Back to cited text no. 8
    
9.
Lazarou J, Pomeranz BH, Corey PN. Incidence of adverse drug reactions in hospitalized patients: A meta-analysis of prospective studies. JAMA 1998;279:1200-5.  Back to cited text no. 9
    
10.
Brvar M, Fokter N, Bunc M, Mozina M. The frequency of adverse drug reaction related admissions according to method of detection, admission urgency and medical department specialty. BMC Clin Pharmacol 2009;9:8.  Back to cited text no. 10
    
11.
Fattinger K, Roos M, Vergères P, Holenstein C, Kind B, Masche U, et al. Epidemiology of drug exposure and adverse drug reactions in two Swiss departments of internal medicine. Br J Clin Pharmacol 2000;49:158-67.  Back to cited text no. 11
    
12.
WHO. International Statistical Classification of Diseases and Related Health Problems, Tenth Revision – ICD-10. World Health Organization; 2007. Available from: www.iacr.com.fr/icd10flyer.pdf. [Last accessed on 2015 Apr 10].  Back to cited text no. 12
    
13.
Zed PJ, Abu-Laban RB, Balen RM, Loewen PS, Hohl CM, Brubacher JR, et al. Incidence, severity and preventability of medication-related visits to the emergency department: A prospective study. CMAJ 2008;178:1563-9.  Back to cited text no. 13
    
14.
Oshikoya KA, Njokanma OF, Chukwura HA, Ojo IO. Adverse drug reactions in Nigerian children. Paediatr Perinat Drug Ther 2007;8:81-8.  Back to cited text no. 14
    
15.
Causality Assessment Algorithms and Scales; 2005. Available from: www.pharmacovigilance.co.in/causalityassessment.html. [Last accessed on 2015 Apr 20].  Back to cited text no. 15
    
16.
Naranjo CA, Busto U, Sellers EM, Sandor P, Ruiz I, Roberts EA, et al. A method for estimating the probability of adverse drug reactions. Clin Pharmacol Ther 1981;30:239-45.  Back to cited text no. 16
    
17.
Moore N, Lecointre D, Noblet C, Mabille M. Frequency and cost of serious adverse drug reactions in a department of general medicine. Br J Clin Pharmacol 1998;45:301-8.  Back to cited text no. 17
    
18.
Rademaker M. Do women have more adverse drug reactions? Am J Clin Dermatol 2001;2:349-51.  Back to cited text no. 18
    
19.
Arulmani R, Rajendran SD, Suresh B. Adverse drug reaction monitoring in a secondary care hospital in South India. Br J Clin Pharmacol 2008;65:210-6.  Back to cited text no. 19
    
20.
Shah RB, Gajjar BM, Desai SV. Drug utilization pattern among geriatric patients assessed with the anatomical therapeutic chemical classification/defined daily dose system in a rural tertiary care hospital. Int J Nutr Pharmacol Neurol Dis 2012;2:258-65.  Back to cited text no. 20
  [Full text]  
21.
Jimoh AO, Omar I, Adebisi IM, Sani Z, Bello A. Review of morbidity profile and drug prescribing patterns of a university clinic in North-Western Nigeria. Int J Med Sci 2014;1:107-15.  Back to cited text no. 21
    
22.
Fadare JO, Agboola SM, Opeke OA, Alabi RA. Prescription pattern and prevalence of potentially inappropriate medications among elderly patients in a Nigerian rural tertiary hospital. Ther Clin Risk Manag 2013;9:115-20.  Back to cited text no. 22
    
23.
American Geriatrics Society 2012 Beers Criteria Update Expert Panel. American geriatrics society updated beers criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc 2012;60:616-31.  Back to cited text no. 23
    
24.
Maio V, Del Canale S, Abouzaid S; GAP Investigators. Using explicit criteria to evaluate the quality of prescribing in elderly Italian outpatients: A cohort study. J Clin Pharm Ther 2010;35:219-29.  Back to cited text no. 24
    
25.
Liu GG, Christensen DB. The continuing challenge of inappropriate prescribing in the elderly: An update of the evidence. J Am Pharm Assoc (Wash) 2002;42:847-57.  Back to cited text no. 25
    
26.
Harugeri A, Joseph J, Parthasarathi G, Ramesh M, Guido S. Potentially inappropriate medication use in elderly patients: A study of prevalence and predictors in two teaching hospitals. J Postgrad Med 2010;56:186-91.  Back to cited text no. 26
[PUBMED]  [Full text]  
27.
Chang CB, Yang SY, Lai HY, Wu RS, Liu HC, Hsu HY, et al. Using published criteria to develop a list of potentially inappropriate medications for elderly patients in Taiwan. Pharmacoepidemiol Drug Saf 2012;21:1269-79.  Back to cited text no. 27
    
28.
Adebayo ET, Hussain NA. Pattern of prescription drug use in Nigerian Army Hospitals. Ann Afr Med 2010;9:152-8.  Back to cited text no. 28
[PUBMED]  [Full text]  
29.
Federal Ministry of Health. National Policy on Malaria Diagnosis and Treatment. National Malaria Control Programme. Abuja, Nigeria: Federal Ministry of Health; March, 2010.  Back to cited text no. 29
    
30.
Zaveri HG, Mansuri SM, Patel VJ. Use of potentially inappropriate medicines in elderly: A prospective study in medicine out-patient department of a tertiary care teaching hospital. Indian J Pharmacol 2010;42:95-8.  Back to cited text no. 30
[PUBMED]  [Full text]  
31.
Guaraldo L, Cano FG, Damasceno GS, Rozenfeld S. Inappropriate medication use among the elderly: A systematic review of administrative databases. BMC Geriatr 2011;11:79.  Back to cited text no. 31
    
32.
Olanrewaju TO, Aderibigbe A, Busari OA, Sanya EO. Antihypertensive drug utilization and conformity to guidelines in a sub-Saharan African hypertensive population. Int J Clin Pharmacol Ther 2010;48:68-75.  Back to cited text no. 32
    
33.
Brattwall M, Turan I, Jakobsson J. Musculoskeletal pain: Prescription of NSAID and weak opioid by primary health care physicians in Sweden 2004-2008 – A retrospective patient record review. J Pain Res 2010;3:131-5.  Back to cited text no. 33
    
34.
Public Alert on Safety of Drugs Marketed/Manufactured in Nigeria and Other Countries. Abuja: National Agency for Food and Drug Administration and Control; 2011. Available from: www.nafdac.gov.ng/index.php/consumers/recalls-alerts/recalls-a-safety-alerts/148-public-alert-on-safety-of-drugs-marketedmanufactured-in-nigeria-and-other-countries. [Last accessed on 2012 Sep 11].  Back to cited text no. 34
    
35.
Tamuno I, Fadare JO. Drug prescription pattern in a Nigerian tertiary hospital. Trop J Pharm Res 2012;11:146-52.  Back to cited text no. 35
    
36.
Isah AO, Ross-Degnan D, Quick J, Laing R, Mabadeje AF. The Development of Standard Values for the WHO Drug Use Prescribing Indicators. INRUD Nigeria/DAP/WHO. Available from: www.archives.who.int/icium/icium1997/posters/1a2_txt.html. [Last accessed on 2017 Aug 18].  Back to cited text no. 36
    
37.
WHO. International Statistical Classification of Diseases and Related Health Problems, Tenth Revision – ICD-10. World Health Organization; 2007. Available from: www.iacr.com.fr/icd10flyer.pdf. [Last accessed on 2017 Sep 10].  Back to cited text no. 37
    
38.
World Health Organization. WHO Collaborating Center for Drug Statistics Methology. Guidelines for Anatomical Therapeutic Classification and Defined Daily Dose Assignment, 2016. World Health Organization; 2017.  Back to cited text no. 38
    


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