With about 60 percent of long-term care patients suffering from depression, many patients have been prescribed antidepressants. But for elderly patients--who often are on several other medications to treat ailments from diabetes to heart disease--adding antidepressants to the mix may mean unwanted side effects.
"If a patient is taking five medications, the potential for drug interactions is estimated to be 50 percent; with eight drugs, it's essentially 100 percent," says Debra Dunivin, PhD, a clinical psychologist at Walter Reed Army Medical Center and one of the nation's few psychologists with credentials enabling her to prescribe.
Interactions may cause discomfort, such as blurry vision, dry mouth and constipation, or damage the heart and be life-threatening. Orthostatic hypertension is especially problematic for elderly individuals in predisposing them to falls and hip fractures.
Psychologists with expertise in psychopharmacology and working with geriatric populations can play a role in educating nursing home staff about the special needs of older adults, says Dunivin. For instance, she says, combined psychosocial and pharmacologic treatments are usually additive in their effect and should be offered together whenever possible.
Unfortunately, medication is often the single means for treating depression in older adults. A major contributing factor is that many older adults have dementia and Medicare has certain coverage restrictions on the use of psychotherapy for patients diagnosed with dementia. The APA Practice Directorate's government relations staff has been working with several state psychological associations to challenge these restrictions through local Medicare carriers.
The controlled-research data indicate that cyclic antidepressants are about twice as effective as placebo in elderly depressed patients, says Dunivin. And remission rates are about 70 percent to 80 percent for nonpsychotic patients when treated with adequate doses. The slower metabolism in older adults is one factor confounding pharmacological treatment of the depressed elderly. Additional factors such as concurrent medical issues and the use of multiple drugs, combined with slower metabolism, complicate the treatment regimen in many elderly patients.
Older adults are more likely to tolerate selective serotonin reuptake inhibitors (SSRIs), such as Prozac and Paxil, and the newer atypical antidepressants, such as Wellbutrin, Effexor and Serzone, because they have relatively mild side effect profiles. Zoloft may be especially useful in treating this population because of its relatively short half-life, lower potential for interactions and ability to be dispensed in smaller doses. Tricyclic antidepressants (TCAs), such as Pamelor and Elavil, are less expensive than SSRIs because they are available in generic form and may be most feasible for people on a fixed income. They may also have superior efficacy in melancholic depression.
"The older drugs may be less expensive, but it can actually be more expensive to treat people with those drugs because their side effects need to be managed on top of the depression and other ailments," says Tom Clark, director of professional affairs for the American Society of Consultant Pharmacists in Alexandria, Va.
Information about drug interactions is available at the Georgetown University Medical Center Pharmacology Department Web site, www.drug-interactions.com.
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