Efficacy of phenytoin for 7 days versus 21 days as prophylactic anticonvulsant in traumatic brain injury patients - A comparative study.

Background: Post traumatic seizures (PTS) are very common after traumatic brain injury and occur more common in severe form of injury. Prophylactic treatment with phenytoin has been found to be effective however till now no uniform internationally agreed guideline is available for the duration of anticonvulsant prophylaxis for traumatic brain injury patients.

Methods: 100 patients of either sex between age group of 18-65 years who have suffered intracranial injury identified by CT scan, admitted in Trauma ICU were enrolled in this prospective randomized single blinded clinical study. Group 1 (n = 50) received 7 days prophylactic anticonvulsant therapy with phenytoin and Group 2 (n = 50) received for 21 days. The primary end point was the occurrence of seizures, which were classified as early (occurring from time of drug loading to day 7) or late (occurring on day 8 or later after loading of drug). Patients were also assessed for the possible adverse side effects of phenytoin.

Result: Out of 100 patients, 90 completed the study successfully as 5 patients from each group expired during the duration of the study. On comparing the frequency of seizure from 1 to 7 day after loading dose of phenytoin between two groups, out of 45 patient, 2 (4.4%) developed seizure in group 1 and 3 (6.7%) developed seizure in group 2 and found to be statistically insignificant (P = 0.645). On comparing the frequency of seizure from 1 to 21 day after loading dose of phenytoin between two groups, out of 45 patient, 4 (8.9%) developed seizure in groups 1 and 3 (11.1%) developed seizure in group 2 and found to be statistically insignificant (P = 0.725).

Conclusion: A 21-day prophylactic anticonvulsant therapy with phenytoin was not more effective than a 7-day prophylactic therapy with phenytoin to reduce the frequency of seizure in a TBI patient in trauma ICU and was also associated with more adverse side effects that were insignificant.