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Year : 2020  |  Volume : 11  |  Issue : 1  |  Page : 19-24

Hospital based intensive medication safety monitoring; an observational prospective study in a north Indian private tertiary care teaching institute

1 Department of Pharmacology, MMIMSR, Maharishi Markandeshwar Deemed to be University (MMDU), Ambala, Haryana, India
2 Department of Pharmacy Practice, National Institute of Pharmaceutical Education and Research, Mohali, Punjab, India

Date of Submission01-Nov-2019
Date of Decision14-Jan-2020
Date of Acceptance06-May-2020
Date of Web Publication12-Sep-2020

Correspondence Address:
Pramil Tiwari
Department of Pharmacy Practice, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar, Mohali - 160 062, Punjab
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jpp.JPP_109_19

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Objective: To identify and characterize adverse drug reactions (ADRs) in patients admitted in intensive care units and wards of a private tertiary care hospital. Materials and Methods: This prospective, observational study was conducted on inpatients. During their hospital stay, whenever a new symptom unrelated to disease or change in laboratory values was observed; ADR was identified using World Health Organisation's definition and recorded in the patient's case sheet. ADRs were classified based on Naranjo's probability scale, Modified Hartwig's criteria of severity and Schumock–Thornton preventability scale. Further, ADRs were analyzed in terms of age, gender, organ system involved, number of medications, and length of stay. Results: Of the 1000 study patients, 35 patients developed 43 ADRs (reported incidence: 3.5%). Twenty-seven patients developed one ADR, while eight patients developed 2 ADRs each. Anti-infective drugs were suspected to have caused the majority (44%) of the ADRs. The most affected organ systems were the gastrointestinal system (44%) and hematological system (26%). On the causality scale, 81.39% ADRs were probably related to suspected medications. About 91% ADRs were probably preventable and 58% ADRs were moderately severe. Number of patients with ADRs was significantly more (P < 0.05) in patients (51.42%) prescribed >11 medications. Further, the number of patients with ADRs was significantly more (P < 0.05) among patients (80%) with a longer stay (>6 days); suggesting, polypharmacy and length of patient's stay as important contributors to developing ADRs. Conclusion: Medication use is majorly associated with the occurrence of ADRs in inpatients. Such surveys on a larger scale would be a useful effort in making medication use safer.

Keywords: Adverse drug reaction, Indian hospital, medication safety, prospective study

How to cite this article:
Sharma V, Tiwari P, Rathod M. Hospital based intensive medication safety monitoring; an observational prospective study in a north Indian private tertiary care teaching institute. J Pharmacol Pharmacother 2020;11:19-24

How to cite this URL:
Sharma V, Tiwari P, Rathod M. Hospital based intensive medication safety monitoring; an observational prospective study in a north Indian private tertiary care teaching institute. J Pharmacol Pharmacother [serial online] 2020 [cited 2021 Mar 5];11:19-24. Available from:

   Introduction Top

There is a significant burden of adverse drug reactions (ADRs) in hospitalized patients. The World Health Organization's (WHO) definition of an ADR is “A 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.”[1] It is estimated that 5%–8% of all hospitalized patients experience serious ADRs and is the 4–6th leading cause of death in US hospitals.[2] Between 1999 and 2008, in England, ADRs were the cause of 0.9% of total hospital admissions.[3] The prevalence of ADRs has been reported to be 0.3%–17% in pediatric intensive care units (ICUs) and 4.5%–34.1% in adult ICUs.[4] The most common drug classes implicated are antimicrobials in medical ICUs, cardiovascular drugs and anticoagulants in coronary care units, and analgesics and sedatives in surgical care units.[4] Further, a systematic review assessing ADRs in children estimated that anti-infectives and anti-epileptics were the most frequently reported therapeutic class associated with ADRs in hospitalized children.[5] The burden of ADRs is expected to be even higher in developing countries due to the extensive prevalence of self-medication, fake and adulterated medicine; therefore, demanding stronger and robust ADR reporting systems. In the Indian context, the median incidence of ADRs in admitted patients, as reported in a review, including prospective studies, was 6.34%.[6] However, there is a paucity of data on ADRs as the monitoring-reporting and pharmacovigilance related practices are still evolving in India for the figures to be truly reflective of the real burden. Hospital-based intensive monitoring is one of the most effective and applicable methods to identify and assess ADRs.[7] Only a few intensive monitoring studies have been published in India. This study was therefore aimed to understand the incidence of ADRs in inpatients of a North Indian private tertiary care hospital and to characterize them for causality, severity, and preventability. Further, this study explores the observed ADRs in terms of the number of medications, hospital stay, implicated medications, and organ systems involved.

   Materials and Methods Top

Study design and study population

This observational prospective study was conducted on admitted patients of a private tertiary care teaching hospital. The study protocol was approved by the Institutional Ethics Committee (ECR/28/inst/PB/2013/RR-16) on October 10, 2018.

Inclusion criteria

Patients admitted to ICUs and wards of the hospital were included in the study.

Exclusion criteria

  • Patients in whom ADRs occurred outside the hospital or in whom ADR was the reason for admission were excluded
  • Patients with overdose, accidental poisoning, drug abuse, medicolegal cases were excluded from the study.

Study procedure

All relevant information was recorded in the patient's case record form. The information that was collected included patient's demographics, admission date, chief complaints, medical history, family history, complete medication history, including known drug allergies. Complete detail of the current prescription, including drug name, dose, frequency, route, time, and date of the order was noted. Laboratory values, daily vitals, doctors, and nursing progress notes were recorded. ADR was identified either subjectively by the appearance of new symptoms, which was not present when therapy was started and was unrelated to disease condition or objectively by observing changes in vitals or laboratory values unrelated to patient's medical condition. These ADRs were then recorded in the patient's file for further assessment. In addition, the ADRs spontaneously reported by doctors or nurses were also included.

Data analysis

The identified ADRs were evaluated using Naranjo's ADR probability scale, which categorizes ADR into definite (score ≥9), probable (score = 5–8), possible (score = 1–4), and doubtful (score <0).[8] ADRs were classified into mild, moderate, and severe using Modified Hartwig criteria for severity assessment.[9] Schumock and Thornton criteria were used to categorize preventability of ADRs into definitely preventable, probably preventable, and not preventable.[10] Based on Rawlins and Thompson classification, each reaction was classified as type A (augmented) or type B (bizarre).[11] The drugs that were suspected to have caused the ADR were coded into various drug classes according to anatomical therapeutic chemical (ATC) classification based on the WHO-ATC Index 2019.[12]

Statistical analysis

All the data were represented as number, average ± standard error mean and percentages. Chi-square test and Proportion Z-test was applied for comparing categorical variables. P < 0.05 was considered statistically significant.

   Results Top

A total of 1000 patients were included in the study. The characteristics of the study patients, including the demographic detail, is shown in [Table 1].
Table 1: Characteristics of the study patients

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Characteristics of study patients

[Table 1] shows that among the 1000 study patients, number of males was more than number of females and maximum patients belonged to the middle age group. Almost all patients were prescribed >10 medications and had an average hospital stay of >5 days.

Characteristics of patients with adverse drug reactions

[Table 2] shows that 35 patients experienced at least one or more ADR during their hospital stay. Of these, 8 patients (4 males, 4 females) had experienced 2 ADRs each and 27 patients (16 males, 11 females) experienced 1 ADR; a total of 43 ADRs were reported in 35 patients. It was observed that males experienced more events than females, but no significant gender predisposition was seen. About 57.14% of the ADRs were observed in the elderly age group. It was found that the number of ADRs significantly (P = 0.019) increased with an increase in the number of medications with maximum ADRs (51.42%) occurring in patients who received ≥11 medications. Further, 44.7% of patients had a hospital stay of 1–5 days, but the percentage of ADRs observed in this group was least (20%), and it was observed that the number of ADRs significantly (P = 0.000016) increased with increase in patient's hospital stay.
Table 2: Characteristics of patients with adverse drug reactions

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Medications causing adverse drug reactions

[Table 3] shows that of the 43 ADRs reported, 44% were suspected to be caused by anti-infective drugs, followed by 21% caused by drugs acting on the nervous system.
Table 3: Medications causing adverse drug reactions and their frequency

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Organ systems involved in adverse drug reactions

[Table 4] shows that the majority (60%) of the ADRs were subjectively identified. The most affected organ systems were the gastrointestinal system (44%) and hematological system (26%). Constipation (19%) was the most frequently identified event followed by thrombocytopenia (16%) and vomiting (14%).
Table 4: Organ systems involved and frequency of adverse drug reactions

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Characterization of adverse drug reactions

[Table 5] shows that the majority of ADRs were Type A. Maximum ADRs were probably related to the suspected drug. On severity scale and preventability scale, maximum ADRs were moderate in nature and probably preventable, respectively.
Table 5: Characterisation of adverse drug reactions according to various scales (n=43)

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   Discussion Top

ADRs are an emergent cause of morbidity and mortality worldwide and represent a serious clinical issue.[2] It is, therefore, important to monitor and report ADRs to the pharmacovigilance bodies. There are various methods of monitoring ADRs. Hospital-based intensive monitoring is one of the most effective methods to identify and assess ADRs.[7] Pharmacovigilance in India is still in its infancy stage, and very less data are available on intensive monitoring. This study was therefore designed to understand the incidence of ADRs in inpatients and to characterize the identified ADRs for causality, severity, and preventability. We also explored the observed ADRs based on polypharmacy, hospital stay, implicated medications, and organ systems involved.

In this study, the incidence of ADRs among hospitalized patients was found to be 3.5%. A similar study conducted in South India reported an incidence of 3.7%, which is comparable to our study.[13] In another Indian study by Doshi et al., the incidence reported was lower (2.1%).[14] This could be because they included patients from only two units of the hospital, unlike our study, in which all units were included. However, a European review reported a higher incidence of 10%, possibly owing to their efficient ADR reporting systems.[15] Patients belonging to the elderly age group experienced a maximum (57.14%) ADRs, but this was in accordance with the number of patients enrolled in each group. The ADRs observed in various categories of age showed no significant difference in this study. Although studies have shown that females have a higher incidence of developing ADRs than males, our study showed no significant difference in various categories of gender.[16] This could be because the female patients (42.1%) included in the study was lesser than the male patients (57.9%). It was observed that the number of ADRs increased with an increase in the number of medications taken by the patient. Majority of the ADRs (51.42%) occurred in patients taking >11 medications, thereby indicating polypharmacy as an important risk factor. This was in concordance with studies by Davies et al. and Thiesen.[17],[18] In a similar study conducted by Rehan et al., it was concluded that more the number of medications more is the risk of developing ADRs.[19] Similarly, it was observed that the number of ADRs increased with an increase in patient's length of stay in the hospital, which was a significant finding (P < 0.05) as also concluded by Davies et al.[17] Antibiotics were implicated to cause 44% of total ADRs in concordance with other studies reporting 47.3%, 35.7%, and 40.62% antibiotics associated events.[19],[20],[21] This could also be related to the fact that antimicrobials are the most commonly and irrationally prescribed class of medications. It is noteworthy that in this study, most of the antibiotic associated ADRs included events such as tachycardia, thrombocytopenia, hypokalemia, and eosinophilia, which were moderately severe in nature, therefore indicating that an antibiotic prescription should be cautiously and judiciously done. The other classes of drugs causing the adverse event episode included drugs acting on the nervous system (21%), including opioid analgesics and drugs acting on blood and blood-forming organs like anticoagulants (16%). A study conducted by Davies et al. also observed opioid analgesics and anticoagulants to be the most commonly implicated class of drugs in causing ADRs.[17] About 44% of ADRs involved gastrointestinal tract followed by 25% ADRs involving hematological system. Similar observations were made in studies done by Ramesh et al. and Doshi et al.[13],[14] 90.7% ADRs were Type A, which are predictable and dose-dependent reactions. Comparable results were seen in studies done by Tiwari et al. and Pirmohamed et al.[22],[23] According to the causality scale, the majority (81.39%) ADRs were probably related to the suspected drug. In the study done by Davies et al., majority (66.5%) of the ADRs were probably related to the suspected drug.[17] On modified Hartwig's Severity Scale, 58% ADRs were moderately severe, as also observed by Ramesh et al.[13] Majority of the ADRs required intervention and discontinuation of the suspected drug and scored level 3 on the severity scale, while a few lead to an increase in the patient's hospital stay (level 4a). About 40% of the ADRs were mild and managed simply by discontinuing the suspected drug. On the modified Schumock and Thornton preventability scale, 91% of ADRs were probably preventable, in which taking appropriate preventive measures such as regular monitoring, daily pharmacist rounds, and intervention could have prevented the event occurrence. 9% of ADRs were not preventable, which mostly included unpredictable bizarre reactions unrelated to the dose of the drug like rashes and itching. A meta-analysis assessing ADRs considered preventable ADRs to be a major burden in inpatients as observed in our study.[24] A limitation of this study is that the patients were not followed up till discharge. The patient enrolled was visited again only to collect data like whether the suspected drug was continued or not if the same was not decided in the first place. Follow-up for understanding the consequences of ADRs would have been more meaningful and informative.

   Conclusion Top

Medication use is significantly associated with the occurrence of ADRs in inpatients. Polypharmacy and patient's increased length of hospital stay are important risk factors for the occurrence of ADRs. In this study, antimicrobials contributed to the majority of the ADRs, highlighting the importance of prudent antimicrobial prescription. Preventable ADRs form a significant burden in hospitalized patients indicating prescribers to be mindful and vigilant of the opportunities for intervention to prevent ADRs and ensure safer medication use.


We would like to thank the patients and attendants, treating physicians, and hospital pharmacists for their support.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

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  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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