Dopamine Augmented Rehabilitation in Stroke (DARS): a multicentre double-blind, randomised controlled trial of co-careldopa compared with placebo, in addition to routine NHS occupational and physical therapy, delivered early after stroke on functional recovery
Authors: Ford Gary A , Bhakta Bipin B , Cozens Alastair , Cundill Bonnie , Hartley Suzanne , Holloway Ivana , Meads David , Pearn John , Ruddock Sharon , Sackley Catherine M , Saloniki Eirini-Christina , Santorelli Gillian , Walker Marion F , Farrin Amanda J 
Published: July 2019

Background
Dopamine is a key modulator of striatal function and learning, and may improve motor recovery after stroke. Seven small trials of dopamine agonists after stroke have provided equivocal evidence of the clinical effectiveness of dopamine agonists in improving motor recovery.

Design
Dopamine Augmented Rehabilitation in Stroke was a multicentre, randomised, double-blind, placebo-controlled trial with stroke patients randomised to receive 6 weeks of co-careldopa (Sinemet®, Merck Sharp & Dohme Ltd) or placebo in combination with occupational and physical rehabilitation.

Methods
The primary outcome measure was the proportion of patients walking independently at 8 weeks [Rivermead Mobility Index (RMI) score of ≥ 7 points and ‘yes’ to item 7 on the RMI]. Secondary outcome measures assessed physical functioning, pain, cognition, mood, fatigue and carer burden at 8 weeks, 6 months and 12 months.

Results
Between May 2011 and March 2014, 593 patients (mean age 68.5 years) and 165 carers (mean age 59.7 years) were recruited from stroke rehabilitation units; 308 patients were randomised to co-careldopa and 285 to placebo at a median of 15 days following stroke onset. The study drug was to be taken 45–60 minutes before therapy, which included motor activities (mean 23.2 and 24.8 sessions in the co-careldopa and placebo groups, respectively). The mean number of investigational medicinal product doses taken was 20.6 in the co-careldopa group and 22.4 in the placebo group. Ability to walk independently was not improved at 8 weeks [40.6% (co-careldopa) vs. 44.6% (placebo); odds ratio 0.78, 95% confidence interval (CI) 0.53 to 1.15], 6 months [51.6% (co-careldopa) vs. 53.3% (placebo)] or 12 months [51.6% (co-careldopa) vs. 56.8% (placebo)]. There were no significant differences for Barthel Index, Nottingham Extended Activities of Daily Living, ABILHAND Manual Ability Measure or Modified Rankin Scale, pain or fatigue at any time point. Montreal Cognitive Assessment scores did not significantly differ; the majority of participants had cognitive impairment at baseline, which improved during 12 months’ follow-up. No difference was observed in General Health Questionnaire 12-item version scores between groups at 8 weeks and 12 months but, at 6 months, those in the co-careldopa group reported significantly better general health [mean difference (MD) –1.33, 95% CI –2.57 to –0.10]. Mortality at 12 months was not significantly different. Carers in the placebo group reported significantly greater burden at 6 months (MD 5.05, 95% CI 0.10 to 10.01) and 12 months (MD 7.52, 95% CI 1.87 to 13.18).

Conclusion
Co-careldopa in addition to routine NHS occupational and physical therapy is not clinically effective or cost-effective in improving walking, physical functioning, mood or cognition following stroke. We recommend further research to develop imaging and clinical markers that would allow identification of promising drug therapies that would enhance motor therapy in improving walking ability and arm function. Further research is needed to compare strategies of giving drug therapy intermittently immediately prior to therapy sessions or as continuous background daily administration.

Limitations
In total, 10.3% of patients were lost to follow-up at 8 weeks and < 10% of patients met the strict per-protocol definition. Despite this, the findings are robust and generalisable to patients with limited mobility in the first few weeks after stroke.

Trial registration
Current Controlled Trials ISRCTN99643613.

Funding
This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership.