I would like to know what happens to the level of dilantin in the blood after 6 hours past the 12 hours period after the last dosage that labs want for blood work timings if no dilantin is taken till the 16 hours mark. This is if the dilantin level is at the top of the theraputic level. My opinion is that the level would go down to the middle of the theraputic range. Am I correct about this opinion?