What medication can improve walking speed and disability in a patient with secondary progressive multiple sclerosis?

Dalfampridine is a medication that has been shown to improve walking speed and reduce disability in patients with secondary progressive multiple sclerosis (SPMS). It works by blocking potassium channels, which enhances action potential conduction in demyelinated or partially demyelinated axons, thus improving nerve signal conduction and ultimately aiding in muscle function related to walking.

In patients with SPMS, where mobility can be significantly affected, enhancing walking speed can lead to a better quality of life and increased functional capabilities. Clinical trials have demonstrated that patients taking dalfampridine can experience meaningful improvements in ambulation, which is crucial for their independence and overall well-being.

Other medications mentioned do not specifically target mobility in multiple sclerosis. Donepezil, primarily used for Alzheimer's disease, focuses on cognitive function. Riluzole is mainly prescribed for amyotrophic lateral sclerosis and has limited relevance to multiple sclerosis walking impairment. Bromocriptine is generally used for conditions like Parkinson's disease and does not have a role in managing the symptoms associated specifically with secondary progressive multiple sclerosis.

Thus, dalfampridine stands out as the effective option for addressing both walking speed and disability in this patient population.