ORGANUM
Phenytoin is used in the management and treatment of epilepsy, generalised tonic-clonic seizures, complex partial seizures, and status epilepticus. It is the anticonvulsants class of drugs.
Phenytoin is available in oral and parenteral formulations. IM administration is not recommended due to its erratic absorption and local reaction. The drug is slowly administered IV directly into a large central or peripheral vein through an IV catheter < 20 gauge, and not exceeding a rate of 50mg/minute. It requires dilution with sodium chloride as crystals may form when diluted with a dextrose solution.
As it is poorly soluble, parenteral phenytoin is available in a solution of propylene glycol and alcohol which are responsible for some of the adverse effects that is seen in IV administration. There is a water-soluble phenytoin available, Fosphenytoin, that can be used in situations where phenytoin is not advisable; IM injection can be given with Fosphenytoin.
Phenytoin is a hydantoin derivative – a first generation anticonvulsant drug that is effective in its treatment of all types of seizures without significantly impaired neurological function. It works by blockages of voltage-dependent membrane sodium channels responsible for increasing the action potential. In seizures, this action obstructs the positive feedback that sustains high-frequency repetitive firing, thus preventing the spread of the seizure focal point.