VARIABILITY OF PHENYTOIN INDUCED GUM HYPERPLASIA IN PATIENTS OF EPILEPSY IN A TERTIARY CARE: THERAPEUTIC DRUG MONITORING OF PHENYTOIN NEEDS VERSATILE AND SPECIFIC METHODOLOGY
Phenytoin is still used as the first choice in epilepsy. It is a well studied drug and due to its ADRs and side effects, TDM is a well defined technique, used in tertiary care centers. It optimizes dosage regimens in patients on phenytoin as it has a narrow therapeutic window. Its use needs vigilance as it has many drug-drug interactions, CNS side effects and gum hyperplasia. Serum drug concentrations guides us that the therapeutic levels be maintained during the course of treatment. Its therapeutic range is 10-20 micrograms/ml. Study was carried in tertiary centre where Neurology department is well established. A total of 1450 patients were enrolled in the study in 5 years period. Patients of (21-30 )years of age group attend maximally, maximum gum hyperplasia was in this age group who were in therapeutic range of phenytoin and patients in the study were taking equal doses in equal intervals of time. Patients had variable response in gum
hyperplasia and it was a retrospective study. Serum concentration was estimated by EMIT System. Out of 1450 patients, only 190 (13.1%) patients developed gum hyperplasia in heterogeneous population viz therapeutic, subtherapeutic or toxic groups. Therapeutic drug monitoring of phenytoin is carried out to ensure effective and safe levels.
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