Drug-Induced Diseases

How Extensive Is the Problem of Specific Adverse Drug Reactions?
Each year, more than 9.6 million adverse drug reactions occur in older Americans. One study found that 37 percent of adverse reactions in the elderly were not reported to the doctor, presumably because patients did not realize the reactions in the elderly are due to the drug. This is not too surprising considering that most doctors admitted they did not explain possible adverse effects to their patients.

We based the following national estimates on well-conducted studies, mainly in the United States:

• Each year, in hospitals alone, there are 28,000 cases of life-threatening heart toxicity from adverse reactions to  digoxin (DIGITEK, LANOXICAPS, LANOXIN), the most commonly used form of digitalis (drugs that regulate the speed and strength of heart beats) in older adults.
• Each year 41,000 older adults are hospitalized — and 3,300 of these die from ulcers caused by NSAIDs (nonsteroidal anti-inflammatory drugs, usually for treatment of arthritis). Thousands of younger adults are hospitalized.
• At least 16,000 injuries from auto crashes each year involving older drivers are attributable to the use of psychoactive drugs, specifically benzodiazepines and tricyclic antidepressants. Psychoactive drugs are those that affect the mind or behavior.
• Each year 32,000 older adults suffer from hip fractures attributable to drug-induced falls, resulting in more than 1,500 deaths. In one study, the main categories of drugs responsible for the falls leading to hip fractures were sleeping pills and minor tranquilizers (30 percent), antipsychotic drugs (52 percent), and antidepressants (17 percent). All of these categories of drugs are often prescribed unnecessarily, especially in older adults.
• Approximately 163,000 older Americans suffer from serious mental impairment (memory loss, dementia) either caused or worsened by drugs. In a study in the state of Washington, in 46 percent of the patients with drug-induced mental impairment, the problem was caused by minor tranquilizers or sleeping pills; in 14 percent, by high blood pressure drugs; and in 11 percent, by antipsychotic drugs.
• Two million older Americans are addicted or at risk of addiction to minor tranquilizers or sleeping pills because they have used them daily for at least one year, even though there is no acceptable evidence that the tranquilizers are effective for more than four months, and the sleeping pills for more than 30 days.
• Drug-induced tardive dyskinesia has developed in 73,000 older adults; this condition is the most serious and common adverse reaction to antipsychotic drugs, and it is often irreversible. Tardive dyskinesia is characterized by involuntary movements of the face, arms and legs. About 80 percent of older adults receiving antipsychotic drugs do not have schizophrenia or other conditions that justify the use of such powerful drugs, so many of these patients have serious side effects from drugs that were prescribed inappropriately.
• Drug-induced parkinsonism has developed in 61,000 older adults also due to the use of antipsychotic drugs such as haloperidol (HALDOL), chlorpromazine (THORAZINE), trifluoperazine (STELAZINE), fluphenazine (PROLIXIN), and thioridazine (MELLARIL). There are other parkinsonism-inducing drugs as well, such as metoclopramide (REGLAN), prochlorperazine (COMPAZINE), and promethazine (PHENERGAN), prescribed for gastrointestinal problems.

A serious problem exists because both doctors and patients do not realize that practically any symptom in older adults and in many younger adults can be caused or worsened by drugs. Some doctors and patients assume that what are actually adverse drug reactions are simply signs of aging. As a result, many serious adverse reactions are entirely overlooked or not recognized until they have caused significant harm.

The drugs responsible for the most serious adverse reactions in older adults are tranquilizers, sleeping pills, and other mind-affecting drugs; cardiovascular drugs such as high blood pressure drugs, digoxin, and drugs for abnormal heart rhythms; and drugs for treating intestinal problems.