Question of the Day – Friday January 5, 2018

Question: 4-Aminopyridine (4-AP) has been used in the treatment of a variety of diseases characterized by poor neuronal transmission including multiple sclerosis, spinal cord injury, botulism, Lambert-Eaton syndrome, and myasthenia gravis. What is the mechanism of action of 4-AP?

Answer: The cited article notes “4-Aminopyridine (4-AP) selectively blocks voltage-gated potassium channels, prolongs the action potential, increases calcium influx, and subsequently, enhances interneuronal and neuromuscular synaptic transmission.” (King AM et al. 4-Aminopyridine toxicity: A case report and review if the literature. 2012 J Med Tox 8:314-321)