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Q: Depakote Dose: Go by Symptoms or Lab Values?
My 17 year old son (200 lbs) is on 2000 mg Depakote qd, 900 mg
Eskalith CR qd and Ambien 3 or 4 x aweek prn and 0.1 mg Synthroid qd. New
doctor reduced Depakote to 1500 qd as lab value was 150 mg. However, that
lab was drawn about 4 hours after he took 1000 mg morning dose. Previous
dr. had us hold the meds for lab draw. Lab says to hold med as the "normal
50 to 100" range is for a trough value. New dr says take meds and friend
who is psych nurse says OK to take meds before draw. Some articles on nets say
max dose for mania isn't set so just go by symptoms. Right now he isn't
manic but mostly sleeps during the day, not in school, not working, becomes very
anxious at any attempt to try to study for GED or driver's permit etc. Any
advice for me? Thank you for your time, I do appreciate it. New doctor is
enthused to try to help my son but I worry the labs are not being monitored
correctly. Perhaps it is OK as long as the draw is consistently after the
meds?
Dear Ms. V' --
You've got all the possible points of view racked up there, don't you? The
one I particularly favor is the "treat the patient, not the lab value"
one. If he was doing great, I'd focus there not on the number. But
since he's not; since some of his current status could be from high
Depakote levels; I'd pay more attention to the numbers than otherwise. So,
now we need more reliable numbers.
For starters, the range of valproate levels that most
mood experts go by these days is 50-125, as there are some people whose mood
symptoms will respond between 100 and 125, but not lower; and the side effects
don't seem to really jump up in frequency until beyond 125. Thus we
psychiatrists, as opposed to the neurologists, use the higher "top
end".
Secondly, in my experience that number refers to a
"trough" sample, all right, from the convention the neurologists have
followed for years. However, with the new Depakote ER pills, blood levels
are not supposed to fluctuate much so I'll sometimes just grab an afternoon
level if I don't really need a precise number -- as is more the issue now in
your son's case. Even then, though, I'd do some discounting of the value
if it were drawn about 4 hours post dose.
But at this point it sounds like it's time to go back
to "how's the patient doing?" Too high a Depakote dose can
produce drowsiness, though usually patients can recognize it as: blurred
vision, mild; headache, mild, kind of an odd one; and "fuzzy" or
"spacey" thinking. Maybe your son at 150 is beyond those more
subtle signs; or maybe it's what they're trying to treat that makes him thus,
and with less Depakote he'll cycle more, or show other signs of bipolar mood
instability.
At this point, the new doc' has launched on a trial of
lower Depakote. Let's see how that works. Now that the dose has come
down a bit, the blood level questions are even more moot, no? But, these
are reasonable questions, especially if you ever have to think about going up on
the dose; or if your son's better, but not better enough, and you're wondering
if you should go lower (although that step I'd probably do even without another
level. I generally use levels if something's wrong and I'm trying to figure out
what, like I think it should be working and it's not; or if we're changing
medications and I want to get a marker in place as something to go back to
later, if necessary, kind of a "stick in the sand").
Last thought: if the Ambien is needed "prn",
i.e. not all the time; and he's sleeping during the day; it sounds like at
minimum his circadian rhythm is disturbed, which is common in adolescents but
sounds more out of whack here. And it sounds like he might still be
cycling, if the Ambien is not needed sometimes, but sometimes is? This,
and the anxiety you describe, look to me like the main targets, maybe even more
important than the daytime somnolence, which would be a secondary issue that
could be due to the circadian problem or the cycling problem (and those two
could be related or one and the same). In that case I'd look, at minimum,
at the "Social Rhythm Therapy" approach: regular sleep, eating,
and activity schedules; even to the point of considering some variant of the
"dark
therapy" approach used at the NIMH (read down to Biological Clocks and Treatment.)
All of that has the advantage of no additional medications, of course.
Beyond that, if he's cycling for sure, then maybe switch T4 to T3/T4?
(very guesswork level data on that, as reported here: Thyroid and Bipolar
Disorder) or add low dose of an additional mood stabilizer? or bump
lithium up to a level (and here all the issues about when to draw, and what the
level is, really do matter!) of 0.8 or 0.9, at least for a
while?
Congratulations on having found a doc' who's enthused
to help your son! You can pass along my thoughts as simply ideas to
consider, since I'm commenting from left field here, or not even mention them if
things are going smoothly. Good luck with all that.
Dr. Phelps
Published March, 2003
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