SAN DIEGO – Patients with mild Alzheimer’s disease who took 20 mg/day of memantine for 1 year remained the same or improved their driving ability, compared with placebo-treated patients in a small pilot trial.
Memantine is currently approved for moderate and severe Alzheimer’s disease (AD), but the findings suggest that the agent may have some neuroprotective qualities for people in the early stages of the disease, Anna Lisa Curtis said in an interview at the Clinical Trials Conference on Alzheimer’s Disease.
"In Florida, we have a large population of elderly that are still on the road, including those with early AD," said Ms. Curtis, a research coordinator at Florida Atlantic University (FAU), Boca Raton. "Being able to help maintain an imperative skill like driving for one’s sense of self and [the] ability to have a broader life is important, as is the safety of pedestrians and other motorists, and caregiver burden."
Anna Lisa Curtis
In a study led by Dr. Peter J. Holland, a psychiatrist at FAU, the researchers set out to evaluate the effects of 20 mg/day of memantine on delaying the progression of driving impairment in 60 men and women with mild AD as measured by actual driving and by a battery of neuropsychological tests focused on the cognitive skills necessary for driving, including executive functioning, visuospatial abilities, attention, and orientation. At baseline, 6 months, and 12 months, driving ability was measured with the DriveABLE-On-Road Test. They tested cognition with ADAS-Cog mazes, Fuld Object-Memory Evaluation, Clinical Dementia Rating scale, Trail-Making Tests A and B, the Rey-Osterrieth Complex Figure Test, the Useful Field of View test, and the Motor Free Visual Perception TestVisual Closure Subtest. The primary outcome was the number of subjects in each group who were able to pass the DriveABLE test at month 12. The secondary outcome measures were the changes from baseline to month 12 on the driving-related neuropsychological battery.
The researchers reported findings from 22 patients in the memantine group and 21 patients in the placebo group. Their mean age was 79 years and 62% were male. In terms of driving ability, 100% of patients in the memantine group remained the same or improved, compared with 75% of those in the placebo group, a difference that reached statistical significance (P = .04). In addition, after controlling for baseline ability, patients in the memantine group performed significantly better on the Rey-Osterrieth Complex Figure Test (P = .05) and on the Trails A and B tests (P = .05 and .02, respectively). Outcomes on the other tests were similar between the two groups.
"We did not anticipate that the treatment group would perform as well as it did," Ms. Curtis said. "In a 12-month period with AD, we can see quite a bit of decline, and we were surprised to see people in the memantine group maintaining skills or actually improving in their capacity."
She concluded that the findings warrant further study on the role of memantine in delaying driving impairment in patients with mild AD.
Forest Laboratories funded the study. Ms. Curtis said that she had no relevant financial conflicts to disclose.