Early results of a randomized controlled clinical trial suggest that the SSRI drug escitalopram (brand names Lexapro, Cipralex) may benefit older adults with generalized anxiety disorder, although it is likely the trial failed to show clear overall benefits compared with placebo because some trial patients dropped out. The researchers said the drug needs to be tested further and cautions doctors to explain this to their patients, along with the side effects which include sleep disturbance and urinary symptoms.
The US and Canadian study was conducted by Dr Eric J Lenze, of Washington University, St. Louis, Missouri, and colleagues, and is published online on 21 January in the Journal of the American Medical Association, JAMA.
Despite being one of the most common psychiatric disorders among older adults, there is not a lot of information about Generalized Anxiety Disorder (GAD) to help doctors make safe and effective decisions about treatment.
GAD is characterized by chronic, difficult-to-control worry and anxiety, and associated symptoms, including muscle tension, sleep disturbance and fatigue. Some 7.3 per cent of older adults in the community have GAD, and this proportion is higher among primary care patients. There is a lack of effective treatments for older adults with GAD, and the urgency to resolve this grows as more older people join the population.
There is evidence that on balance, SSRIs (selective serotonin reuptake inhibitors) work with younger GAD patients, but we don’t know if the balance of risks and benefits is the same for older adults.
For the study, Lenze and colleagues recruited 177 participants aged 60 and over from primary care practices and specialty clinics in Pittsburgh, Pennsylvania. The participants had a principal diagnosis of GAD and were randomized to receive either escitalopram (85 patients) or placebo (92 patients) for a 12 week period from January 2005 to January 2008. The dose was 10 to 20 mg a day for the 12 weeks.
Anxiety, emotional and social function, and other outcomes were assessed using a range of recognized tools, including the Clinical Global Impressions-Improvement score, the Hamilton Anxiety Rating Scale, the Penn State Worry Questionnaire, and the Late-Life Function and Disability Instrument activity limitations subscale.
The results showed that the patients on the active drug responded to treatment more and more as the weeks went on (the cumulative incidence of response to treatment score was higher), when compared to those on placebo (69 versus 51 per cent respectively).
Compared to placebo patients, the escitalopram patients also showed greater improvement in: anxiety symptoms and role functioning; and in activity limitations and impairments in role and social functioning.
From an analysis that included those that began the trial but then dropped out (the ITT or intention to treat analysis), the researchers found no difference in response between the active drug and the placebo groups. 16 (18.5 per cent) of the escitalopram patients dropped out before the study finished at week 12, and 17 (18.4 per cent) of the placebo patients had also dropped out by week 12.
In the escitalopram group, adverse effects included fatigue or sleepiness, sleep disturbance and urinary symptoms.
The authors concluded that:
“Older adults with GAD randomized to escitalopram had a higher cumulative response rate for improvement vs placebo over 12 weeks; however, response rates were not significantly different using an intention-to-treat analysis. Further study is required to assess efficacy and safety over longer treatment durations.”
“Given the high human and economic burden of GAD, these data should provide impetus to detect and treat this common disorder,” they wrote.
The researchers also noted that it was important for doctors to explain to patients that further tests are needed before we can be sure of the drug’s benefits, and also to make sure they understand the side effects.
“Escitalopram for Older Adults With Generalized Anxiety Disorder: A Randomized Controlled Trial.”
Eric J. Lenze; Bruce L. Rollman; M. Katherine Shear; Mary Amanda Dew; Bruce G. Pollock; Caroline Ciliberti; Michelle Costantino; Sara Snyder; Peichang Shi; Edward Spitznagel; Carmen Andreescu; Meryl A. Butters; Charles F. Reynolds, III.
JAMA. 2009;301(3):295-303.
Vol. 301 No. 3, published online January 21, 2009.
Sources: JAMA press release, journal abstract.
Written by: Catharine Paddock, PhD