Dear Anne --
Two very practical questions. First,
about single daily dosing: we don't have the information needed to assure you
that a single daily dose will work as well for bipolar control. It would
not be expected to work as well for seizure control, where "therapeutic" blood
levels through the day are important to maintain. Once-a-day dosing would
produce too much of a peak-and-trough in those blood levels for control of
epilepsy. But what about bipolar disorder?
We actually know that once-a-day lithium is effective for
bipolar control. This suggests that "therapeutic blood levels" may not transfer
directly, as a concept, from epilepsy to bipolar disorder. Maybe it's not so
important to have 24-hour exposure to lithium, or at least to a given blood
level of lithium.
But, does this extend to anticonvulsants like Trileptal?
Now that the Depakote manufacturer has made an "extended release" formula,
once-a-day Depakote is acceptable -- because the peak/troughs produced using
that pill are small. The blood levels are relatively constant over 24 hours.
But this is not the case for Trileptal, which requires twice-a-day dosing to
keep from having pretty deep troughs.
So, the answer is, "don't know"; at least I don't know
that we can assure you that once-daily-dosing will not lead to any greater risk
of relapse than daily. However, one could reason like this: suppose your son
misses doses on a twice-daily-dosing basis about a third of the time. Now he's
really just taking 600 mg of Trileptal. By comparison, if it's the morning dose
he always forgets, and you switch to an evening dose schedule, he could actually
end up with higher blood levels overall.
This presumes he can tolerate 900 mg at a time. My
patients often seem to start getting side effects at about 900 twice daily, 1800
total; and quite a few can tell the difference between their morning 600 and
their evening 1200 when I have them split the dose like that.
In any case, urge him to discuss dosing plans for maximal
benefit with his doctor. I would defer to the doctor's judgment regarding the
wisdom of once-a-day in your son's case. With my patients, I might try it for a
while watching very closely for signs of relapse, but that's playing with
fire I prefer to avoid if possible.
Question two: antipsychotic first, or more mood
stabilizer? Probably depends on the symptoms. If psychotic, most psychiatrists
would recommend the antipsychotic (although personally I think that's from
simplistic logic rather than research or even good clinical observation; though
it's in the standard recommendations for treatment one sees all the time). If
the symptoms are mild and we're not looking at a need for urgent,
definitely-going-to-work strategies, I'd pick the option with the fewest side
effects in the long run that might make your son's inclination to take
medications even lower. In particular nowadays this means watching out for
weight gain potential.
Published January, 2004