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Some Psychotropics May Be Inappropriate for the Elderly
by Kenneth J. Bender, Pharm.D., M.A.
Geriatric Times March/April 2001 Vol. II Issue 2
Despite their accounting for only 14% of the population, the elderly receive more than one-third of all prescribed medications (Shelton et al., 2000). This high prescription rate, coupled with their decreased capacity to clear medications, already deems the elderly susceptible to adverse drug reactions. In addition to this, a new study found that 27.2% of psychotropic prescribing for elderly outpatients may be inappropriate (Mort and Aparasu, 2000).The study investigators applied the Beers consensus-developed criteria for identifying potentially inappropriate medication use in patients over 65 years of age in their screening of almost 30,000 patient record forms collected in the 1996 National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) by the National Center for Health Statistics (NCHS).
Jane Mort, Pharm.D., and Rajender Aparasu, Ph.D., characterized the potentially inappropriate prescribing they identified as a "major issue in the effort to optimize care for the elderly while avoiding excessive costs associated with adverse outcomes."
What the Survey Found
Extrapolation of the survey data, based on the patient sampling weight provided by the NCHS, yielded an estimated 16.55 million visits to physician offices and outpatient departments in the United States in 1996 in which psychotropics were prescribed. This was approximately 8.7% of all clinic visits made by the elderly, or 51.97 visits for every 100 people aged 65 years or older.
Psychotropic medications were deemed potentially inappropriate based upon susceptibility of the elderly to particular adverse drug effects or because of a patient's particular disease state at the time of prescription. The available survey data from the NCHS precluded considering prescribed dosage.
From the two surveys, 1,373 patient records were found to involve psychotropic prescriptions, and 309 of these appeared potentially inappropriate from the applied criteria. Mort and Aparasu projected that approximately 4.5 million visits nationwide (27.2% of those involving psychotropic prescriptions) involved at least one potentially inappropriate psychotropic prescription.
Most (94.14%) of the psychotropic prescriptions screened as potentially inappropriate for elderly patients were independent of disease state, while 12.13% appeared inappropriate, because of existing illness. Prescriptions for antidepressants and anxiolytics were most often deemed potentially inappropriate independent of disease state, while antidepressants and sedative/hypnotic agents were most often identified based on patients' illness.
The tricyclic antidepressant (TCA) amitriptyline (Elavil) was the psychotropic most frequently identified as potentially inappropriate, having more anticholinergic and sedative effects than newer classes of antidepressants. Long-acting benzodiazepines were the most frequently identified anxiolytics because of their accumulation from repeated dosing and sedative effect. Both psychotropics and anxiolytics are associated with falls and resultant fractures in the elderly.
Mort and Aparasu indicated, "[Amitriptyline use] is rarely justified for the elderly because safer antidepressants are available." They argue, further, "By focusing on amitriptyline and long-acting benzodiazepines, physicians can significantly change inappropriate prescribing for and quality of life of the elderly."
Striving for Safe Prescribing in Elderly
Although this caution against the use of amitriptyline in the elderly is based partially on the TCAs causing more orthostasis and interference with psychomotor function than the selective serotonin reuptake inhibitor antidepressants, an earlier study suggested that falls and fractures in the elderly using antidepressants are not averted by selecting the newer agents (Bender, 1999). A pharmacoepidemiology study by Purushottam Thapa, M.S., M.P.H., and colleagues at Vanderbilt University found TCAs and SSRIs comparable in increasing elderly patients' risk for falling (1998).
These investigators conducted a retrospective analysis of records from 180 days of treatment of 2,428 nursing home residents who either were antidepressant nonusers or had newly prescribed antidepressants. Six hundred sixty-five patients received TCAs or other heterocyclic antidepressants, 612 received SSRIs, and 304 received trazodone (Desyrel). There were 3,524 falls occurring in the 1,460 person-years studied. The elderly patients receiving SSRIs had 80% more falls than matched patients not receiving antidepressants, and those receiving TCAs had twice the number of falls than their matches. This similarly heightened risk of falling with TCAs and SSRIs was also found in another study, which assessed rates of hip fractures subsequent to falls (Liu et al., 1998).
This evidence of comparable risk of falling with TCA and SSRI use does not negate the finding of Mort and Aparasu that the use of amitriptyline is potentially inappropriate in the elderly, since their finding is also based on the greater risk for cardiovascular complications with TCAs than with newer antidepressants. It does reflect, however, the heightened susceptibility of the elderly to react adversely even to medications that meet criteria as appropriate for having relatively safer side-effect profiles. It also points to the difficulties in establishing and applying criteria for inappropriate prescribing.
Prescribing found outside the criteria by Mort and Aparasu was qualified as "potentially" inappropriate because the investigators lacked data on how the drugs were dosed and monitored or the potential drug benefits outweighed the apparent risks. In addition, in a separate review of the Beers criteria, Aparasu and Mort (2000) noted that the medications included as potentially inappropriate reflected opinion differences as well as the consensus of the experts on the criteria development panel.
Some of the cardiovascular medications listed in the Beers criteria as potentially inappropriate, such as methyldopa (Aldomet), reserpine and propranolol (Inderal), "were considered appropriate by some researchers because they have been shown to decrease morbidity and mortality, and a therapy change may not be in the best interest of adequately managed patients."
Consensus-developed criteria remain valuable in assessing whether prescribing is appropriate despite these limitations, argued Aparasu and Mort, as long as the criteria are frequently evaluated and refined, and the findings are reasonably interpreted. Prescribing falling outside these criteria can only be considered as potentially inappropriate until further evaluation. "Criteria can only suggest the likelihood and potential ramifications in terms of adverse outcomes, and are used until studies are done that actually measure outcomes," Aparasu and Mort concluded.
References
Aparasu RR, Mort JR (2000), Inappropriate prescribing for the elderly: Beers criteria-based review. Ann Pharmacother 34(3):338-346.
Bender KJ (1999), Assessing antidepressant safety in the elderly. Psychiatric Times 16(1):51-52.
Liu B, Anderson G, Mittmann N et al. (1998), Use of selective serotonin reuptake inhibitors or tricyclic antidepressants and risk of hip fractures in elderly people. Lancet 351(9112):1303-1307 [see comments].
Mort JR, Aparasu RR (2000), Prescribing potentially inappropriate psychotropic medications to the ambulatory elderly. Arch Intern Med 160(18):2825-2831.
Shelton PS, Fritsch MA, Scott MA (2000), Assessing medication appropriateness in the elderly: a review of available measures. Drugs and Aging 16(6):437-450.
Thapa PB, Gideon P, Cost TW et al. (1998), Antidepressants and the risk of falls among nursing home residents. N Engl J Med 339(13):875-882 [see comments].
