Amifampridine (phosphate)

Amifampridine (3,4-Diaminopyridine) phosphate is an orally active, potent and cell permeable voltage-gated potassium (K_v) channel blocker (PCB). Amifampridine phosphate is efficacy in the reversal of BoNT/A (HY-P79153) intoxication. Amifampridine phosphate increases transmitter release from neuromuscular junctions (NMJs). Amifampridine phosphate can be used for Lambert-Eaton myasthenic syndrome (LEMS) research^[1][2][3]. In Vitro:Amifampridine phosphate (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^[3].
Amifampridine phosphate (0-100 μM) increases the duration of the presynaptic AP (action potential) waveform at mammalian and frog NMJs in a dose-dependent manner^[3]. In Vivo:Amifampridine phosphate (Oral gavage; 10 mg/kg; once) can antagonize muscle paralysis following BoNT/A intoxication^[2].
Amifampridine phosphate (2.5 mg/kg (IV); 10 mg/kg (PO); once) shows 1 hour plasma half-life and about 57% bioavailability (F) in mice^[2].
Amifampridine phosphate has a short plasma half-life and can induce seizures when present at high concentrations, following penetration of the blood-brain barrier^[2].