Amifampridine

Amifampridine is predominantly in the treatment of a number of rare muscle diseases. Amifampridine works by blocking potassium channel efflux in nerve terminals so that action potential duration is increased. Ca2+ channels can then be open for a longer time and allow greater acetylcholine release to stimulate muscle at the end plate. (In Vitro) :Amifampridine (1.5 μM) significantly reduces Kv3.3 and Kv3.4 currents by about 10% in HEK293T cells, has no effect on Cav2.1 or Cav1.2 current.Amifampridine (0-100 μM) increases the duration of the presynaptic AP (action potential) waveform at mammalian and frog NMJs in a dose-dependent manner. (In Vivo) :Amifampridine (Oral gavage; 10 mg/kg; once) can antagonize muscle paralysis following BoNT/A intoxication.Amifampridine (2.5 mg/kg (IV) ; 10 mg/kg (PO) ; once) shows 1 hour plasma half-life and about 57% bioavailability (F) in mice.Amifampridine has a short plasma half-life and can induce seizures when present at high concentrations, following penetration of the blood-brain barrier.