Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03652870 |
| Other study ID # |
18/0279 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
Phase 3
|
| First received |
|
| Last updated |
|
| Start date |
March 5, 2021 |
| Est. completion date |
April 30, 2023 |
Study information
| Verified date |
May 2023 |
| Source |
University College, London |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This is a randomised trial in a NHS setting, comparing the clinical effectiveness and
cost-effectiveness of the selective serotonin reuptake inhibitor, escitalopram, and of the
tricyclic antidepressant, nortriptyline, to placebo, undertaken in a real-life setting in
addition to standard psychological care for the treatment of patients with depression in
Parkinson's disease. Participants will be randomly allocated 1:1:1 to receive escitalopram or
nortriptyline or placebo.
Description:
Parkinson's disease is a progressive neurological disorder that leads to increasing
disability and functional decline. Currently no medications have been shown to halt or delay
disease progression and one of the most common complications in patients with this diagnosis
is depression . Depressive disorders which affects approximately 40% of patients with
Parkinson's disease. They are linked to functional impairment, cognitive decline and faster
disease progression and are the main determinant of poor quality of life in Parkinson's
disease. Psychological therapies are used via standard access to appropriate psychological
services in the NHS, but often antidepressant medications are required. Despite the high
incidence of depression in this population, However, no conclusive evidence on appropriate
choice of antidepressants in Parkinson's disease exists in the NHS, and the risk of worsening
of Parkinsonism and aggravation of non-motor features of Parkinson's disease by
antidepressants pose particular challenges in this population.
Based on the previous evidence from small trials, the hypothesis is that both selective
serotonin reuptake inhibitors and tricyclic antidepressants are effective compared to placebo
and the difference in efficacy between tricyclic antidepressants and selective serotonin
reuptake inhibitors is likely to be small, but that the tolerability of selective serotonin
reuptake inhibitors is higher in this population than that of tricyclic antidepressants due
to the rate of adverse effects. The trial is designed to have statistical power to identify
effects that are clinically important and slightly smaller than the pooled effects identified
in the existing trials of selective serotonin reuptake inhibitors.
Escitalopram is an selective serotonin reuptake inhibitor similar to citalopram, the most
widely used selective serotonin reuptake inhibitor in the UK. Both citalopram and
escitalopram, the S-enantiomer, are now off-patent with comparable costs and similar trial
results. Until recently, escitalopram has been used less commonly in the NHS as because it
was more expensive. However comparative trial data in major depression (including
non-industry funded research) suggest that escitalopram is more effective than citalopram
with similar or lower rates of side effects, and that it is associated with increased
probability of response in trials of older patients with dementia and agitation. In addition,
it has been reported that escitalopram has the highest probability of remission and is the
most effective and cost-effective pharmacological treatment in a primary care setting.
Amitriptyline is the most widely used tricyclic antidepressants in the UK, but is used
predominantly at low doses for pain and insomnia in Parkinson's disease. The side effect
profile of amitriptyline makes it poorly tolerated in patients with Parkinson's disease at
higher, antidepressant doses. Nortriptyline is a metabolite of amitriptyline. However, unlike
amitriptyline it has mainly noradrenergic effects, and weakly blocks dopaminergic reuptake.
It also has fewer sedative, α1-blocking and anticholinergic effects than amitriptyline (by a
factor of 8). It has been evaluated in multiple trials over several decades and its efficacy
and adverse event profile in depressive disorders has been well studied. The trial evidence
on tricyclic antidepressants in depression in Parkinson's disease mainly reports on
nortriptyline and desipramine (which is not available in the NHS). Whilst nortriptyline has a
slightly higher cost than amitriptyline in the NHS, nortriptyline is a more appropriate
medication for treatment of depression in this population. In addition, there is accumulating
evidence from pre-clinical studies that nortriptyline may delay disease progression in
Parkinson's disease.
Patients who meet eligibility criteria at the screening visit will be randomly assigned to
receive 52 weeks of double-blind treatment with either escitalopram, or nortriptyline or
placebo in a 1-1-1 ratio.
For the first two weeks of double-blind treatment, participants aged 65 years and under will
be instructed to take one tablet per day of study drug, containing either 5 mg escitalopram
or 25mg nortriptyline or placebo. Thereafter, the daily study medication dosage will be
increased by one tablet per day, at two-weekly intervals, to a maximum of four tablets per
day unless a subject is experiencing troubling side effects. In those aged over 65 years and
in those with hepatic impairment the dose will be increased to two tablets after 2 weeks
only, from 5 mg escitalopram to 10mg escitalopram or from 25 nortriptyline to 50mg
nortriptyline.
After the primary endpoint at 8 weeks, all participants will continue on the same dose until
the study visit at 52 weeks with an intermediate assessment at 26 weeks. Following the study
assessment after 52 weeks on medication, the trial drug will be tapered off over 4 weeks in
dose reductions of 25 mg for nortriptyline and 5mg for escitalopram every week (4 weeks for
participants 65 years or under and 2 weeks for participants aged over 65 years or those with
hepatic impairment).