Adverse Drug Reactions: How Serious Is the Problem and How Often and Why Does It Occur?

Although some adverse drug reactions are not very serious, others cause the death, hospitalization, or serious injury of  more than 2 million people in the United states each year, including more than 100,000 fatalities. In fact, adverse drug reactions are one of the leading causes of death in the United States. Most of the time, these dangerous events could and should have been avoided. Even the less drastic reactions, such as change in mood, loss of appetite, and nausea, may seriously diminish the quality of life.

Despite the fact that more adverse reactions occur in patients 60 or older, the odds of suffering an adverse drug reaction really begin to increase even before age 50. Almost half (49.5%) of Food and Drug Administration (FDA) reports of deaths from adverse drug reactions and 61% of hospitalizations from adverse drug reactions were in people younger than 60.2 Many physical changes that, affect the way the body can handle drugs actually begin in people in their thirties, but the increased prescribing of drugs does not begin for most people until they enter their fifties. By then, the amount of prescription drug use starts increasing significantly, and therefore the odds of having an adverse drug reaction also increase. The risk of an adverse drug reaction is about 33% higher in people aged 50 to 59 than it is in people aged 40. 3

Adverse Reactions to Drugs Cause Hospitalization of 1.5 Million Americans Each Year

An analysis of numerous studies in which the cause of hospitalization was determined found that approximately 1.5 million hospitalizations a year were caused by adverse drug reactions.4 This means that every day more than 9,000 patients have adverse drug reactions so serious that they need to be admitted to American hospitals. Although the rate; of drug-induced hospitalization is higher in older adults (an average of about 10% of all hospitalizations for older adults are caused by adverse drug reactions) because they use more drugs, a significant proportion of hospitalizations for children is also caused by adverse drug reactions. In a review of more than 6,500 admissions of children to five different hospitals, 2.0% were prompted by adverse drug reactions. 5

Adverse Reactions Occur to 770,000 People a Year During Hospitalization

In addition to the 1.5 million people a year who are admitted to the hospital because of adverse drug reactions, an additional three quarters of a million people a year develop an adverse reaction after they are hospitalized. According to national projection, based on a study involving adverse drug reactions developing in almost 800,000 patients a year, more than 2,000 patients a day, suffer an adverse event caused by drugs once they are admitted. Many of the reactions in the patients studied were serious, even life-threatening, and included cardiac arrhythmias, kidney failure, bleeding, and dangerously low blood pressure. People with these adverse reactions had an almost twofold higher risk of death compared to other otherwise comparable hospitalized patients who did not have a drug reaction. Most importantly, according to the researchers, almost 50% of these adverse reactions were preventable. Among the kinds of preventable problems were adverse interactions between drugs that should not have been prescribed together (hundreds of these are listed in Chapter 3 of this book), known allergies to drugs that had not been asked about before the patients got a prescription, and excessively high doses of drugs prescribed without considering the patient’s weight and kidney functions.

Thus, adding the number of people with adverse drug reactions so serious that they require hospitalization to those in which the adverse reaction was “caused” by the hospitalization, more than 2.2 million people a year, or 6,000 patients a day, suffer these adverse reactions. In both situations, many of these drug-induced problems should have been prevented.

Dangerous Prescribing Outside the Hospital for 6.6 Million Older Adults a Year

Based on the Do Not Use principle we have advocated concerning certain drugs for more than ten years in our Worst Pills, Best Pills books and monthly newsletter, several published studies have examined the extent to which people are prescribed drugs that are contraindicated because there are safer alternatives. One study, whose authors stated that “Worst Pills, Best Pills stimulated this research,” found that almost one out of four older adults living at home–6.6 million people a year were prescribed a “potentially inappropriate” drug or drugs, placing them at risk of such adverse drug effects as mental impairment and sedation, even though the study only examined the use of a relatively short list of needlessly dangerous drugs (fewer than the number listed as Do Not Use drugs in this book).7

Other researchers looked not only at people for whom a contraindicated drug was prescribed, but also at prescriptions for older people involving two other categories: questionable combinations of drugs and excessive treatment duration. The authors categorized all of this as “high-risk prescribing” and limited their analysis to just the three classes of drugs most commonly causing drug-related illness: cardiovascular drugs, psychotropic drugs (ones that act on the mind) such as tranquilizers and antidepressants, and anti-inflammatory drugs. They found that 52.6% of all people 65 or older were given one or more prescriptions for a high-risk drug.8 Thus, more than twice as many older adults were the victims of high-risk prescribing when these two additional categories were added.

Article published in Worst Pills, Best Pills News, November 2010 issue, Vol. 16, No. 11.

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