MS Drug Dalfampridine now Available in US Helps Patients Walk
The drug dalfampridine has been approved by the FDA and is now available in the United States for treatment of impaired walking associated with multiple sclerosis. Dalfampridine was approved in January by the FDA, and is the first oral therapy for multiple sclerosis that can be taken by mouth.
Dalfampridine helps patients with multiple sclerosis walk, by promoting nerve impulse conduction rather than reducing inflammation like other medications used to treat MS.
Two phase III clinical studies of dalfampridine helped patients with multiple sclerosis improve walking speed of twenty five percent among 35 percent of patients in one trial. In the other trial, 43 percent of patients experienced improved walking ability.
Dalfampridine was explored in a small study in 1983, and injected into eleven patients with motor dysfunction from multiple sclerosis. The results were “stunning,” says Dr. Dusan Stefoski, director of Rush University Multiple Sclerosis Center "After a single intravenous dose, the patients could walk better and see better."
Dalfampridine was originally used in Bulgaria to help patients awaken from anesthesia. The drug was being studies in the lab for its effect on nerve conduction at the same time.
A combination of observations by Dr. Floyd Davis, a neurologist in training in the 1960’s and later a physician at Rush University Medical Center led to discovery o dalfampridine for treating patients with multiple sclerosis. First, Dr. Davis found out that patients with MS can walk better when their temperatures are even slightly lower.
The now retired Dr. Davis explains, "In multiple sclerosis, the protective myelin sheath that wraps around nerve fibers in the brain and spinal cord is damaged, essentially causing a short circuit. Somehow, lower body temperature enabled the electrical pulse to continue its travel along the nerve fibers. I was completely transfixed by the significance of that fact."
Next Dr. Davis embarked on a series of lab studies to understand why symptoms of MS improved. He found the chemical 4-aminopyridine, or dalfampridine, which blocks the potassium ion channels in nerve fibers, acting in the same way as lowering body temperature.
Dalfampridine is now available in the United States, and is sold under the brand name Ampyra; marketed by Acorda.
The debilitating effects of multiple sclerosis lead to difficulty walking. Dalfampridine, approved for sale in the United States to help patients with all types of multiple sclerosis walk can also help with other symptoms that include balance loss, fatigue, and memory problems, because it improves signals in all affected nerve fibers.