Trial Outcomes & Findings for Phenytoin as a Neuroprotective Agent Against Corticosteroid-induced Functional Imaging Changes (NCT NCT00591006)

Results Overview

The Rey Auditory Verbal Learning Test (RAVLT) evaluates a wide diversity of functions, including short-term auditory-verbal memory, and retention of information. Test raw scores are converted to T-scores. T-scores have a mean of 30 ± 10 where higher scores are indicative of better verbal memory. Total T-score differences following study treatment interventions are reported.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

17 participants

Primary outcome timeframe

At end of each treatment condition (on average 21 days between treatments)

Results posted on

2015-08-19

Participant Flow

Enrollment began 3/11/2008 and was completed 4/23/2009. Subjects were recruited through flyers posted at UTSW medical clinics.

Subjects were enrolled and randomized to one out of 4 treatments. The study design is a 4-phase crossover study, meaning all subjects received all four treatments during the course of the study. Subjects washed out of each medication cycle for 21 days before beginning the next treatment cycle. Total number of subjects enrolled is 17.

Participant milestones

Participant milestones
Measure	PH + PL Then PL + H Then PL + H Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400 mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by hydrocortisone (160 mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + PL Then PH + H Then PL + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PL + PL Then PH + PL Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours (20mg) and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PH + PL Then PL + PL Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PH +H Then PH + PL Then PL + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + H Then PH + PL Then PH + H Then PL + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PL + H Then PL + PL Then PH + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PH + PL Then PL + PL Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + H Then PL + PL Then PH + PL Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + H Then PL + PL Then PL + H Then PH + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + PL Then PL + PL Then PL + H Then PH + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + PL Then PH + H Then PL + H Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + H Then PH + PL Then PL + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + PL Then PL + H Then PH + H Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + H Then PL + H Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + PL Then PL + H Then PL + PL Then PH + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400 mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.
Overall Study STARTED	1	1	1	1	1	1	1	1	1	2	1	1	1	1	1	1
Overall Study Treatment #2	1	1	1	1	1	1	1	1	1	2	0	1	1	1	1	1
Overall Study Treatment #3	1	1	1	1	1	1	1	1	1	2	0	1	1	1	1	1
Overall Study Treatment #4	1	1	1	1	1	1	1	1	1	2	0	1	1	1	0	0
Overall Study COMPLETED	1	1	1	1	1	1	1	1	1	2	0	1	1	1	0	0
Overall Study NOT COMPLETED	0	0	0	0	0	0	0	0	0	0	1	0	0	0	1	1

Reasons for withdrawal

Reasons for withdrawal
Measure	PH + PL Then PL + H Then PL + H Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400 mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by hydrocortisone (160 mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PH + PL Then PL + H Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400 mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160 mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + PL Then PH + H Then PL + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PL + PL Then PH + PL Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours (20mg) and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PH + PL Then PL + PL Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + H Then PL + PL Then PH + H Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PL + H Then PH +H Then PH + PL Then PL + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + H Then PH + H Then PL + PL Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PL + H Then PH + PL Then PH + H Then PL + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PL + H Then PL + PL Then PH + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PL + H Then PH + PL Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PH + H Then PH + PL Then PL + PL Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + H Then PL + PL Then PH + PL Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + H Then PL + PL Then PL + H Then PH + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing hydrocortisone also at 0900 hours and 2100 hours (160mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + PL Then PL + PL Then PH + H Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + PL Then PL + PL Then PL + H Then PH + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + PL Then PH + H Then PL + PL Then PL + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PH + PL Then PH + H Then PL + H Then PL + PL Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + PL Then PL + H Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by placebo. The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + PL Then PH + H Then PH + PL Then PL + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + PL Then PL + H Then PH + PL Then PH + H Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.	PL + PL Then PL + H Then PH + H Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take phenytoin (400mg/day) followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PL + PL Then PH + H Then PL + H Then PH + PL Participants take two capsules containing placebo tablets by mouth at 0900 hours and 2100 hours for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the placebo), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking phenytoin tablets (400mg/day) followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by hydrocortisone. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by placebo. The imaging will be performed at 1300 hours.	PH + PL Then PL + H Then PL + PL Then PH + H Participants take two capsules containing phenytoin tablets by mouth at 0900 hours and 2100 hours (400 mg/day) for three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Two days prior to the imaging (the day after initiating the phenytoin), participants will begin taking 4 tablets containing placebo also at 0900 hours and 2100 hours with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will repeat this cycle, instead taking placebo tablets followed by hydrocortisone (160mg/day). The imaging will be performed at 1300 hours and participants washout for 21 days. Participants then take placebo followed by placebo. The imaging will be performed at 1300 hours. Participants washout for 21 days. Participants will then take phenytoin followed by hydrocortisone. The imaging will be performed at 1300 hours.
Overall Study Withdrawal by Subject	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	0	0	0	0	0	1
Overall Study Adverse Event	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0

Baseline Characteristics

Phenytoin as a Neuroprotective Agent Against Corticosteroid-induced Functional Imaging Changes

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Total Study Population n=17 Participants Seventeen healthy controls, in a one-hour imaging session, received a structural MRI, MRS and fMRI scan four separate times with a 21 day washout between each study drug exposure in a crossover design. Prior to each scan each participant received placebo + placebo, phenytoin + placebo, hydrocortisone + placebo, or hydrocortisone + phenytoin in a random fashion. Thus, each participant received each of the four possible study drug combinations in a random order with an extended drug washout between each exposure. Hippocampal activation, volume and biochemistry, as well as mood and memory was assessed.
Age, Categorical <=18 years	2 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	15 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Age, Continuous	27.1 years STANDARD_DEVIATION 9.6 • n=5 Participants
Sex: Female, Male Female	9 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants
Region of Enrollment United States	17 participants n=5 Participants

PRIMARY outcome

Timeframe: At end of each treatment condition (on average 21 days between treatments)

The Rey Auditory Verbal Learning Test (RAVLT) evaluates a wide diversity of functions, including short-term auditory-verbal memory, and retention of information. Test raw scores are converted to T-scores. T-scores have a mean of 30 ± 10 where higher scores are indicative of better verbal memory. Total T-score differences following study treatment interventions are reported.

Outcome measures

Outcome measures
Measure	Phenytoin&Hydrocortisone n=15 Participants Examining all participants for the condition in which they took both phenytoin and hydrocortisone.	Placebo&Placebo n=16 Participants Examining all participants for the condition in which they took placebo for both administrations.	Phenytoin&Placebo n=16 Participants Examining all participants for the condition in which they took phenytoin and placebo.	Placebo&Hydrocortisone n=15 Participants Examining all participants for the condition in which they took placebo and hydrocortisone.
Difference in RAVLT Total T-Score Between Treatments	57.76 T-score Standard Error 0.51	56.11 T-score Standard Error 0.67	53.08 T-score Standard Error 0.45	42.76 T-score Standard Error 2.60

SECONDARY outcome

Timeframe: At the end of each treatment condition

Outcome measures

Outcome measures
Measure	Phenytoin&Hydrocortisone n=13 Participants Examining all participants for the condition in which they took both phenytoin and hydrocortisone.	Placebo&Placebo n=15 Participants Examining all participants for the condition in which they took placebo for both administrations.	Phenytoin&Placebo n=15 Participants Examining all participants for the condition in which they took phenytoin and placebo.	Placebo&Hydrocortisone n=14 Participants Examining all participants for the condition in which they took placebo and hydrocortisone.
Hippocampal Activation Differences Between Treatment Conditions	1.035 percentage of BOLD activation Standard Deviation 0.180	1.288 percentage of BOLD activation Standard Deviation .06	1.135 percentage of BOLD activation Standard Deviation 0.161	1.121 percentage of BOLD activation Standard Deviation 0.144

SECONDARY outcome

Timeframe: At the end of each treatment condition

Outcome measures

Outcome measures
Measure	Phenytoin&Hydrocortisone n=13 Participants Examining all participants for the condition in which they took both phenytoin and hydrocortisone.	Placebo&Placebo n=15 Participants Examining all participants for the condition in which they took placebo for both administrations.	Phenytoin&Placebo n=15 Participants Examining all participants for the condition in which they took phenytoin and placebo.	Placebo&Hydrocortisone n=14 Participants Examining all participants for the condition in which they took placebo and hydrocortisone.
Para-Hippocampal Activation Differences Between Treatment Conditions	1.293 percentage of BOLD activation Standard Deviation 0.264	1.604 percentage of BOLD activation Standard Deviation 0.315	1.464 percentage of BOLD activation Standard Deviation 0.246	1.401 percentage of BOLD activation Standard Deviation 0.202

Adverse Events

Placebo, Then Placebo

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Phenytoin, Then Hydrocortisone

Serious events: 1 serious events

Other events: 0 other events

Deaths: 0 deaths

Phenytoin, Then Placebo

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Placebo, Then Hydrocortisone

Serious events: 1 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Placebo, Then Placebo n=15 participants at risk Hydrocortisone, Phenytoin Phenytoin, Dilantin : participants will take two capsules containing phenytoin tablets (100 mg) or identical placebo by mouth at 0900 hours and 2100 hours (400 mg/day) for a total of three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Beginning two days prior to the imaging (the day after initiating the phenytoin or placebo), participants will begin taking 4 tablets containing hydrocortisone (20 mg) or placebo also at 0900 hours and 2100 hours (160 mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours.	Phenytoin, Then Hydrocortisone n=16 participants at risk Placebo, Placebo Phenytoin, Dilantin : participants will take two capsules containing phenytoin tablets (100 mg) or identical placebo by mouth at 0900 hours and 2100 hours (400 mg/day) for a total of three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Beginning two days prior to the imaging (the day after initiating the phenytoin or placebo), participants will begin taking 4 tablets containing hydrocortisone (20 mg) or placebo also at 0900 hours and 2100 hours (160 mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours.	Phenytoin, Then Placebo n=16 participants at risk Phenytoin, Placebo Phenytoin, Dilantin : participants will take two capsules containing phenytoin tablets (100 mg) or identical placebo by mouth at 0900 hours and 2100 hours (400 mg/day) for a total of three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Beginning two days prior to the imaging (the day after initiating the phenytoin or placebo), participants will begin taking 4 tablets containing hydrocortisone (20 mg) or placebo also at 0900 hours and 2100 hours (160 mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours.	Placebo, Then Hydrocortisone n=14 participants at risk Hydrocortisone, Placebo Phenytoin, Dilantin : participants will take two capsules containing phenytoin tablets (100 mg) or identical placebo by mouth at 0900 hours and 2100 hours (400 mg/day) for a total of three days with the last dose at 0900 hours on the day of the imaging (7 doses total). Beginning two days prior to the imaging (the day after initiating the phenytoin or placebo), participants will begin taking 4 tablets containing hydrocortisone (20 mg) or placebo also at 0900 hours and 2100 hours (160 mg/day) with the last dose at 0900 hours on the day of the imaging (5 doses total). The imaging will be performed at 1300 hours.
General disorders MRI anxiety	0.00% 0/15 • Throughout entirety of trial	0.00% 0/16 • Throughout entirety of trial	0.00% 0/16 • Throughout entirety of trial	7.1% 1/14 • Number of events 1 • Throughout entirety of trial
Nervous system disorders Pre-existing condition discovered during MRI	0.00% 0/15 • Throughout entirety of trial	6.2% 1/16 • Number of events 1 • Throughout entirety of trial	0.00% 0/16 • Throughout entirety of trial	0.00% 0/14 • Throughout entirety of trial

Other adverse events

Adverse event data not reported

Additional Information

E. Sherwood Brown

The University of Texas Southwestern Medical Center

Phone: 214 645 6950

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place