Fosphenytoin Sodium is the sodium salt form of fosphenytoin, a prodrug that is hydrolyzed to the anticonvulsant phenytoin. It is an PDE3 (phosphodiesterase 3) inhibitor. Phenytoin exerts its effect most likely through an enhancement of sodium efflux from neurons in the motor cortex. This leads to a suppression of excessive neuronal firing and spread of seizure activity. Other physiologic effects from actions of phenytoin include modulation of the voltage-dependent calcium channels of neurons, inhibition of calcium flux across neuronal membranes and enhancement of sodium-potassium ATPase activity of neurons and glial cells.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.