Abstract
Background and objectives
Accidental and intentional poisonings or drug overdoses constitute a significant source of aggregate morbidity, mortality, and health care expenditure. Studies evaluating drug related hospitalization have estimated that approximately 5–10% of all hospital admissions are drug related. The present study was carried out to investigate type, nature and incidence of drug related admissions in our hospital settings.
Method
A hospital based retrospective study was conducted in 575 cases of drug related admissions. The case records of patients admitted in various clinical departments of Amrita Institute of Medical Sciences (AIMS) Hospital during last 8 years (January 2002–December 2009) were collected and analyzed.
Results
During the retrospective study, the total number of drug related cases reported were 575. Out of these, 35.5% cases were induced by central nervous system (CNS) drugs, 19.8% were by cardiovascular system (CVS) drugs, 12.3% were by NSAIDs, 11.3% were by antibiotics and 9.9% were by anticoagulants, 11.3% by other drugs which includes hormones, cytotoxic drugs, hypolipidemics, etc. Four hundred and forty cases were admitted to emergency department. Common drug related problems resulting in hospital visits were due to intentional, accidental and overdose. The incidence of drug related hospital admissions was found to be 0.20%.
Conclusion
The most of the accidental and suicidal cases were reported are by CNS drugs. Psychiatric patients intentionally taking medicines as suicidal attempt and as a part of their illness. As drug related problems are so significant, increased awareness and enhanced collaborative efforts among patients, physicians, pharmacists and caregivers within community and hospital have the potential to minimize the impact of this problem.
Keywords: Drug related problem, Hospital admission, Poisoning, Over dose
1. Introduction
Over the past 40 years, advances in drug therapies have both improved patient care and led to an apparent increase in the incidence of drug related problems being reported. Before 1960s, there were fewer drugs available and drug related problems were not systematically assessed. Literature from this time focused on adverse drug reactions. Problems relating to complications of drug therapy resulting in significant illness and hospital admission were first highlighted in 1969 (Einarson, 1993; Winterstein et al., 2002). This early work was followed by reports from other groups including the Boston Collaborative Drug Surveillance program. These initial studies put the frequency of such hospital admissions as 1.8–6.2% (Hallas et al., 1993). The proportion of elderly emergency admissions that were drug related hospital admissions (DRHA) varied between 15% and 22% in Australian studies. This is considerably higher than in studies that also included younger patients (Chan et al., 2001). In Australia an incidence of between 2.4% and 3.6% was found and in the United States an incidence of between 3.1% and 6.2% was found. European studies performed in medical departments admissions due to certain ADRs according to WHO (World Health Organization) criteria encounter 3.2% in France and 6.2% in Germany of all admitted patients, while in a prospective computerized event monitoring study in internal medicine departments in Swiss general and teaching hospitals admissions were due to ADRs encounter 3.3% (Fattinger et al., 2000; Pouyanne et al., 2000). In a UK study of ADR related admissions in all hospitals using the computer-assisted International Classification of Diseases (ICD) coding system ADR related admissions represented 0.5% of total hospital admissions (Patel et al., 2007). A study in India carried out in a tertiary referral center in South India showed that admissions due to ADRs accounted for 0.7% of total admissions and deaths due to ADRs accounted for 1.8% of total ADRs (Ramesh et al., 2003).
When medications are prescribed for patients for the treatment of disease, the full intent of all parties involved should be the achievement of an optimal therapeutic outcome. Optimal therapeutic outcome has been defined as an absence of drug-related problems (DRPs) (Roxburgh and Degenhardt, 2008; Howard et al., 2008). A DRP is defined as an event or circumstance that involves a patient’s drug treatment that actually, or potentially, interferes with the achievement of an optimal outcome (Easton et al., 2004; Hepler and Strand, 1990). Unresolved or unrecognized DRPs may manifest as drug-related morbidity, which has been described as the phenomenon of therapeutic malfunction or miscarriage the failure of a therapeutic agent to produce the intended outcome. If left untreated, drug-related morbidity may ultimately lead to drug-related mortality. There is a considerable body of literature that suggests that a large proportion of drug-related morbidity is preventable. The cost of drug-related morbidity and mortality in the ambulatory setting is considerable and should be considered in health policy decisions with regard to pharmaceutical benefits. On the basis of data obtained in the early 1990s, Johnson and Bootman (1995) estimated that, on average, $76.6 billion is spent annually in the ambulatory setting in the United States to resolve DRPs, with drug-related hospitalizations being the largest component of this cost (Ernst and Grizzle, 2001). Policies and services should be developed to reduce and prevent drug-related morbidity and mortality (Koh et al., 2003; Zargarzadeh et al., 2007). Purpose of the study was to investigate type, nature and incidence of drug related admissions in a tertiary care hospital in south India.
2. Method
A retrospective study was conducted in the Medical Record room of Amrita Institute of Medical Sciences and Research Center Hospital (AIMS), Kochi. This is a 1200 bedded tertiary care teaching hospital providing specialized healthcare services to all strata of people in and around Kerala. The complete project work was done according to the permission granted by the ethical committee of AIMS Hospital and according to the permission granted from Medical Records Department of AIMS Hospital, Kochi. The case records of patients admitted in various clinical departments of AIMS Hospital during last 8 years (January 2002–December 2009) were collected and analyzed. All the patients admitted with drug related problems were included in the study and the incomplete records were excluded. Using a data collection form, information on the cases was obtained. In addition to demographic variables like age and sex, the factors of interest considered were diagnosis, drug involved for reaction, drug class and nature of drug related problems, etc. This retrospective data base of patients with drug related admission to the hospital between the specified periods was used to investigate the incidence of drug related problems. Percentage calculations, Microsoft word and Excel have been used to generate tables, etc.
3. Result and discussion
The present study is aimed at evaluating the incidence of drug related hospital admissions in a South Indian hospital. In addition to this the type of drugs associated with the hospitalization are also reported. During our retrospective study, the total number of drug related hospital admissions were found to be 0.20%. A Meta analysis with 95 studies was reported, a range of prevalence of medication-related hospitalizations from 0.1% to 54% was found (Leendertse et al., 2010). These variances in reported prevalence are as a result of the study setting, the studied population, the method of data collection and the continent in which the study is performed. Combined studies in Europe show lower prevalence of medication-related hospital admissions than in other continents included in the study (Leendertse et al., 2010). A review of Australian studies published were identified as 2.4–3.6% of which all the hospital admissions were reported to be drug related (Roughead et al., 1998).
While assessing the data it was confirmed that most of the drugs causing the drug induced hospitalizations were contributed by the CNS drugs (Table 1). Meta analysis of Australian studies published from 1988 to 1996 reported that the most commonly implicated drug groups were cytotoxics, cardiovascular agents, anticoagulants and nonsteroidal anti inflammatory drugs (Roughead, 1999). In another study, antithrombotics showed the highest incidence (0.24%) of drug related admissions (Schneeweiss et al., 2001).
Table 1.
Number of drug related problems.
| Sl. No. | Class of drugs | No. of drug related cases (N = 575) | % |
|---|---|---|---|
| 1 | Central nervous system drugs. | 203 | 35.5 |
| 2 | Cardiovascular drugs | 114 | 19.8 |
| 3 | NSAIDs | 71 | 12.3 |
| 4 | Antibiotics | 65 | 11.3 |
| 5 | Anticoagulant | 57 | 09.9 |
| 6 | Others (hormones, cytotoxic, oral hypoglycemic drugs and hypolipidemic drugs) | 65 | 11.3 |
NSAIDs, non-steroidal anti-inflammatory drugs.
Medications that act on the central nervous system (35.5%) were most often related to a trauma. In our study over dose toxicity is the common reason for emergency admissions due to CNS drugs. In a similar study that was reported CNS drugs contributed for 5.1% of cases (Leendertse et al., 2008). In another study, CNS drugs most commonly involved were drugs of abuse (23.2%) and anticonvulsants (17.1%) (Prince et al., 1992) (Table 2).
Table 2.
CNS drugs vs. DRP cases.
| CNS drugs | Nature of DRP | No. of cases | Department |
|---|---|---|---|
| Phenytoin | Overdose | 89 | Emergency |
| Phenobarbitone | Overdose Drug reaction |
10 4 |
Emergency |
| Alprazolam | Overdose | 44 | Emergency |
| Carbamazepene | Overdose Drug reaction |
14 6 |
Emergency |
| Lorazepam | Overdose | 12 | Emergency |
| Levodopa | Drug reactions | 8 | Emergency |
| Trifluperazine | Overdose | 9 | Emergency |
| Trihexylphenydyl | Overdose | 4 | Emergency |
| Haloperidol | Drug reactions | 3 | Emergency |
| Total DRP cases | 203 |
CNS, central nerves system; DRP, drug related problem.
CVS drugs were the second contributing category drugs for drug related hospitalizations. The major drugs of this category were presented in Table 3. Among these drugs thiazide diuretics were identified as contributors of hyponatremia were as antiarrhythmics contributed to toxicities. Almost similar result was found in another study where CVS drugs contributed to 18.3% of the emergency visits (Patel and Zed, 2002). Dartnell et al. found that 5.7% of emergency admissions to hospital over a period of 1 month were drug-related, with 83 drugs being implicated. Over 30% of these medications included antihypertensives, diuretics, anticoagulants and other cardiovascular drugs (Miller et al., 2001).
Table 3.
CVS drugs vs. DRP cases.
| CVS drugs | Nature of DRP | No. of cases | Department |
|---|---|---|---|
| Beta-blockers | Overdose Drug reactions |
7 22 |
Emergency |
| ACE inhibitors | Drug reactions | 20 | Cardiology |
| Diuretics | Drug reactions | 20 | Internal medicine |
| Nitrates | Drug reactions | 6 | Internal medicine |
| Angiotensin-II receptor blockers | Drug reaction | 7 | Internal medicine |
| Digoxin | Overdose | 15 | Emergency |
| Amiodarone | Drug reactions | 14 | Internal medicine |
| Calcium channel Blocker | Overdose | 3 | Internal medicine |
| Total DRP cases | 114 |
CVS, cardio vascular system; DRP, drug related problem; ACE, angiotensin converting enzyme.
In our study 12.3% of drug related hospitalizations cases were due to NSAIDs. A UK study estimated that 1.9% of NSAID users were admitted to hospital each year with upper gastrointestinal emergencies (Blower et al., 1997). There are clear differences in risk with different NSAIDs, and some clearly are associated with higher risks of upper gastrointestinal bleeding than others. In this study, we have found that Aspirin is the main reason for hospital admission in 69% of cases among NSAID users. While the Italian study demonstrated a particularly high risk with ketorolac (Garcia Rodriguez et al., 1998). A new study reveals that NSAIDs such as Ibuprofen increases the risk of a hospital admission for the condition by 30% (Table 4).
Table 4.
NSAIDs drugs vs. DRP cases.
| NSAIDs | Nature of DRP | No. of cases | Department |
|---|---|---|---|
| Aspirin | Drug reactions | 49 | Emergency |
| Celecoxib | Overdose Drug reactions |
8 4 |
Internal medicine |
| Indomethacin | Drug reactions | 6 | Internal medicine |
| Nimesulide | Drug reactions | 4 | Internal medicine |
| Total DRP cases | 71 |
NSAIDs, non steroidal anti inflammatory drugs; DRP, drug related problem.
Antibiotics were also found to have a significant contribution to the category of drug related admissions (11.3%). Drugs included were sulfasalazine, amino glycosides, antileprotics, antitubercular and tetracyclines. Aminoglycoside induced toxicities were mostly ototoxicities mainly caused by streptomycins. Antileprotics–dapsone induced methaemoglobinaemia and ATT–rifampicin induced hepatitis, drug reactions were also reported. Almost similar results were revealed by a retrospective review of drug related visits to hospital emergency departments over a period of one year in US. This antibiotic contributes for 15.4% of the cases (Patel and Zed, 2002) (Table 5).
Table 5.
Antibiotics vs. DRP cases.
| Antibiotics | Nature of DRP | No. of cases | Department |
|---|---|---|---|
| Aminoglycosides | Overdose Drug reaction |
2 22 |
Internal medicine |
| Sulfonamides | Overdose Drug reaction |
3 9 |
Internal medicine |
| Antituberculars | Drug reaction | 13 | Pulmonary medicine |
| Antileprotics | Drug reaction | 10 | Dermatology |
| Tetracyclines | Drug reaction | 6 | Internal medicine |
| Total DRP | 65 |
DRP, drug related problem.
In our study anticoagulants were responsible for 9.9% of cases of drug related hospital admissions. These were due to acute gum bleedings, upper gastrointestinal bleedings and allergic reactions caused by these drugs. Various studies had shown antithrombotics had highest incidence of hospitalization (Schneeweiss et al., 2001). In a Netherland study, medication associated with potentially preventable hospital admissions were those that affect blood coagulation, such as antiplatelet drugs (8.7%), oral anticoagulants (6.3%), NSAIDs (5.1%), and a combination of these medicines (10.5%) (Leendertse et al., 2008) (Table 6).
Table 6.
Anticoagulants Vs. DRP cases.
| Anticoagulants | Nature of DRP cases | No. of DRP cases | Department |
|---|---|---|---|
| Aspirin | Overdose | 27 | Emergency |
| Warfarin | Overdose | 18 | Emergency |
| Clopidogrel | Drug reactions | 12 | Emergency |
| Total DRP | 57 |
DRP, drug related problem.
Other classes of drugs such as cytotoxic drugs, hypolipidemic, antihistamines, and oral hypoglycemic agents were remarkably causing drug related hospitalizations (Table 7). Steroid induced cases were cushing syndrome, myopathies and hypoglycemia caused by drugs like prednisone and betamethasone.
Table 7.
Other Drugs vs. DRP cases.
| Other drugs | Nature of DRP | No. of cases | Department |
|---|---|---|---|
| Cytotoxic drugs | Overdose Drug reaction |
11 21 |
Internal medicine |
| Oral hypoglycemics | Overdose | 14 | Internal medicine |
| Hypolipidemics | Overdose | 12 | Internal medicine |
| Antihistamines | Drug reaction | 7 | Emergency |
| Total DRP | 65 |
DRP, drug related problem.
The antidotes given below were found to be prescribed in corresponding over dose cases. Sometimes it may be given as discharge medications or as the course of medication during the hospital stay (Table 8).
Table 8.
Drugs vs. Antidotes.
| Drugs | Antidotes |
|---|---|
| Benzodiazepenes | Flumazanil |
| Antipsychotics (extrapyramidal reactions) | Diphenhydramine hydrochloride + benzetropine mesylate |
| Opiods | Nalozone hydrochloride |
| Lorazepam | Flumazanil |
| Beta-blockers | Theophylline |
| Digoxin | Digoxin Immune Fab |
| Calcium channel blockers | Glucagon/insulin |
| Warfarin | Phytome-a-dione (Vitamin-K) |
| Isoniazid | Pyridoxine |
| Aspirin | Activated charcoal |
| Metformin | Octreotide |
| Carbamazepene | Activated charcoal |
4. Conclusion
A broad and comprehensive definition of drug related admissions indicates that these are significant problems within the health system, with up to 0.20% of admissions to hospital being drug related. The most frequently implicated drug classes are drugs acting on central nervous system, cardiovascular drugs, antibiotics and NSAIDs.
This study highlights the need for a greater awareness for drug related admissions. The solution to this problem is enhanced collaborative efforts among patients, physicians, pharmacists and caregivers within the community and the hospital. Recognition of patient, prescriber, drug and disease factors as well as appropriate therapeutic modification, should be pursued. This can be enhanced by a research focus on current studies that identify preventable events accurately, to explore how they happen and how to prevent them.
Contributors
Sonal Sekhar designed the study, analyzed the data and wrote the manuscript and shall act as the guarantor for the paper; Adheena Mary collected the data, helped in data analysis and manuscript preparation; Anju collected the data and helped in analysis and Nishana Ameer Hamsa critically reviewed the manuscript.
Funding source
Nil.
Conflict of interest
The authors declare that there is no conflict of interest on this research study.
Acknowledgments
We deeply express our profound and sincere gratitude to all the staff of the Medical Records Department, AIMS Hospital and Dr. K.G. Revikumar, Principal, Amrita School of Pharmacy for the valuable guidance and encouragement.
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