Need for 25 mg tablets of phenytoin.

Phenytoin is widely used for the treatment of generalized tonic clonic and partial seizures. Monitoring of serum phenytoin levels is essential to optimize therapy. Of 320 patients monitored, 190 patients whose seizures were uncontrolled were followed up before and after dosage adjustment was carried out. Plasma phenytoin estimation was done by HPLC method. Of all the patients receiving the drug, 20% and 8% of patients were finally on dosages requiring 50 and 25 mg fraction administration respectively. Administration of 100 mg fractions resulted in either loss of seizure control or toxicity. This emphasizes the need for providing tablets of 25 mg strength, presently not available in this country.