Adverse drug reactions definitions

Edwards, I.R. and Aronson, J.K., Adverse drug reactions Definitions, diagnosis, and management, Lancet, 356, 1255, 2000. 

Edwards RI, Aronson JK. Adverse drug reactions definitions, diagnosis and management. Lancet 2000 356 1255-9. 

Assessment of Suspected Adverse Drug Reactions Definition... 

Bedi N, Chilvers C, Churchill R et al. Assessing effectiveness of treatment of depression in primary care. Partially randomised preference trial. Br J Psychiatry 2000 177 312-18 Edwards IR, Aronson JK. Adverse drug reactions definitions, diagnosis, and management. Lancet 2000 356 1255-9... 

Approximately 30-40% of patients will not respond to a given antidepressant and 60-75% may fail to achieve complete remission [16]. Consequently, in its least restricted definition, treatment resistance could be detected in the majority of depressed patients under treatment. Moreover, prior treatment failure negatively influences the response to subsequent antidepressant treatment, decreasing the odds of treatment response by a factor of 15-20% for each failed treatment [17]. The delayed onset of symptom relief (which takes three to eight weeks to occur) and the presence of adverse drug reactions contribute significantly to low treatment compliance. 

Fig. 7.1 Relationship between Drug-related Problems (DRP), Adverse Drug Reaction (ADR), and Adverse Drug Event (ADE). The definitions of extrinsic and intrinsic DRPs have been adapted from van den Bent (2002)... 

Drug-related problems can be defined as Any undesirable event experienced by the patient that involves or is suspected to involve drug therapy and that actually or potentially interferes with a desired patient outcome (Strand et al. 1990). This is a vital component of Pharmaceutical Care and Clinical Pharmacy and will be described more in detail in another chapter. It should however be noted that there are several definitions and classification systems for DRPs. A literature review (van Mil et al. 2004) identified fourteen classifications and their critical elements. In the presented definition a potential problem is a DRP but this is not the case in all definitions and classifications. This is also the case for unavoidable adverse drug reactions (e.g. with cytotoxic agents). 

There is no universal definition of polypharmacy. One common definition is the use of five or more drugs. This is also the definition that we use in this book. With increasing number of drugs the risk for adverse drug reactions increases. 

Synonyms of adverse reactions generally include adverse medical effects, untoward effects, side effects, adverse drug experiences, and adverse drug reactions. Specific distinctions among some of these terms may be defined operationally. For example, the term adverse reaction is used to denote those signs and symptoms at least possibly related to a medicine, whereas the term adverse experience is used to include nonmedicine-related medical problems in a trial such as those emanating from trauma or concurrent illness. Distinctions among side effects, adverse events, and adverse reactions are illustrated in the definitions of the two former terms. 

However, the temptation to link glutathione (GSH) adducts to MBI must be avoided since the identification of metabolite adducts with GSH does not confirm MBI, albeit it may be an indicator of other adverse drug reactions (Walgren et al., 2005). By definition, exogenous nucleophiles such as GSH should offer no protection from MBI [161], and in principle, even when GSH adducts are formed from the same chemical entity responsible for MBI, the exogenous adducts themselves may not be related to the enzyme-inactivating species [174]. 

There is considerable confusion in the use of terminology in this area. Edwards and Aronson proposed the following definition. An adverse drug reaction is an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product, which predicts hazard from future administration and warrants prevention... 

CIOMS. Standardisation of definitions and criteria of causality assessment of adverse drug reactions -drug-induced cytopenia. Int J Clin Pharmacol Tker Toxicol 1991 29 75-81. 

Adverse drug reactions and drug interactions W McCaughey Introduction Definitions Adverse reactions Drug interactions Pharmacokinetic Pharmacodynamic Clinically important interactions INTRODUCTION... 

ICH E2A provides a definition of adverse drug reaction that is applicable during preapproval clinical experiences with a new medicinal product ... 

Although some adverse drug reactions are minor and resolve without sequelae/ others can cause permanent disability or death. ADRs occur commonly/ but estimates of incidence vary considerably. This is due to substantial underreporting of ADRs and differences in study methodology/ populations studied/ and ADR definitions. Adverse drug reactions account for 2.9-15.4% of all hospital admissions in the... 

American Society of Health-System Pharmacists. Suggested definitions and relationships among medication misadventures, medication errors, adverse drug events, and adverse drug reactions. Am J Health-Syst Pharm 1998 55 165-6. 

In a review of definite or probable drug-associated pancreatitis spontaneously reported to the Dutch adverse drug reactions system during 1977-98, azathioprine was the suspected drug in four of 34 patients, two of whom had positive rechallenge (37). Although most of the carefully described reports of azathioprine-induced pancreatitis were found in patients with inflammatory bowel disease, transplant recipients can also suffer this complication. 

A definite case of pancreatitis proven by positive rechallenge was also briefly cited in a review of drug-associated pancreatitis spontaneously reported to the Dutch adverse drug reactions system (261). 

American Society of Health-System Pharmacists. Suggested Definitions and Relationships Among Medication Misadventures, Medication Errors, Adverse Drug Events and Adverse Drug Reactions. Am. J. Health-Syst. Pharm. 1998, 55, 165-166. 

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