Q: Muscle Fatigue & Lamictal
Hi there. My specific question is this: I have been titrating up on Lamictal (still on lithium @ 1200) and I've had a number of side-effects - most
of which have abated.
I am currently on 150, having titrated up very slowly. I have been on 150 for
nearly a week so far, and will remain on this dose for another week before
titrating up to 200.
I have experienced a variety of side-effects such as nausea, muscle aches,
agitation and fatigue, and, once I got to 50 mgs, a kind of "pseudo-hypomania"
that lasted a week: mind-racing, insomnia, mild mood elevation.
While these symptoms have resolved themselves, one symptom hasn't: muscle
weakness. If I wasn't a woodwind player who uses a very demanding mouthpiece and
hard reed I might not have noticed. But it is still pronounced and makes playing
tiring and difficult - my embouchure lacks strength and endurance.
I have read, anecdotally, that some regular gym-goers have noticed this effect
but what I haven't been able to establish is: when does it go away? How does one
establish whether it is a transient side-effect or possibly a more enduring
issue? What is the time frame?
Dear Mr. W. --
Interesting, but I'm sure very frustrating -- and that
is probably an understatement, for a professional musician.
I fear I will not be of great use here, but I do have two thoughts. First, the
range of side effects that you report on lamotrigine (Lamictal) is somewhat
surprising, as most people experience none of these. Moreover, because of the
"mild mood elevation" and other features of hypomania that you describe, I would
be inclined to lump the agitation and perhaps the muscle aches as well with this
phenomenon, rather than a "side effect", like nausea. Although this is not
widely recognized, several other bipolar or specialists I have spoken with are
also quite certain, from clinical experience, that lamotrigine can sometimes act
rather more like an antidepressant, precipitating all these. Less clear is what
to do at that point: for example, is it reasonable to continue to lamotrigine as
long as it is being used with a mood stabilizer? Many of these symptoms diminish
as the dose is reduced, but it is still unclear to me whether lamotrigine is
worth continuing under these circumstances.
Thus, I am not entirely certain that your "muscle fatigue" should be
interpreted as a "side effect". However, and this would be my second thought, it
is very clear that lamotrigine can interfere with balance and muscle
coordination. Although I generally have only seen this at doses of 200 mg and
higher, you might be noting it now because you are so attuned, through your
music, to any changes in muscle tone. Usually this side effect appears alongside
some mild cognitive impairment: people have more difficulty remembering words,
remembering peoples names, and they just don't feel quite mentally sharp. This
diminishes as the dose is reduced and with only one or two exceptions, I have
not seen it at a dose of 200 mg or less.
Of course you would not want to try turning the lamotrigine down on your own.
There might be a way in which this represents some sort of interaction with
lithium, as lithium can also cause muscle fatigue, and nausea, particularly if
you are blood level is high, and you are dose is sufficient to get many people
to a quite high blood level. In fact, and this perhaps should have been my first
thought, it might be wise to get a lithium level, based just on the physical
sensations you are reporting, make sure your level is not too high.
Interestingly, when people are really manic, they often need a higher lithium
dose to get a sufficient blood level; and then later, a much lower dose can
maintain that same blood level. Given that you are being prescribed lamotrigine,
you are probably less likely to have a big episode of mania in your recent past,
but perhaps there is something similar going on here: if lamotrigine was really
doing something, perhaps it could lower your need for lithium (this is all just
speculation, mind you, extrapolating from the observation above about lithium
levels in people who are really manic). Suffice it to say that you should make
any changes from here only in close consultation with your psychiatrist.
Published September, 2007