Q:  Concerns About Lithium

A friend of mine has been taking lithium for what the doctor calls a mild bipolar disease very successfully for 12 years. He was a freshman in college when it was diagnosed and is 31 years old now. He is checked every three months for blood levels. He was told initially that lithium could damage his kidneys, thyroid and/or other organs. He is concerned about this now and wonders if he should stop taking the medication or if there is something else that he could take that would be better. He is doing very well but is reluctant to talk about it even to his doctor. He feels shame and doesn't want anyone to know. I have tried to explain to him that it is a chemical imbalance and is an illness that he should think of as nothing more than the diabetes or any disease that someone else would have. I would appreciate any information that you could give me.


Dear Mr. M'
Good of you to be so concerned, and to try to help.  At minimum, you can continue to urge your friend not to stop the lithium without a clear plan, with the doctor's knowledge who's prescribing it, of what to watch for and what the response will be.  There are well-documented examples of people who've responded well to lithium for years going off the medication, getting symptoms again, then going back on and it doesn't work anymore, or works much less well and has to be augmented with something else.  So, that's step one.  

Step two: the kidney function changes that lithium can cause, after taking it for a long time (more like 15-20 years, and usually this is a concern when for all that time the blood levels have been relatively high), can be detected with a simple blood test.  We look at two tests of kidney function, the Blood Urea Nitrogen and the Creatinine.  BUN can wobble about quite a bit, but creatinine is usually pretty steady.  It would be unusual for both to be abnormal without some sort of kidney problem.  So, if they're both normal, that is supposed to be reassuring.  

It's not 100% reassuring, as the kidney can lose a great deal of its' ability to function and yet have those tests be normal, or close enough that they aren't clearly abnormal.  We have more kidney power than we need so you can lose a lot and still be okay (that's why you can give one away to someone if they need yours...).  So I can't say, "hey, no worries, mate: if you're BUN and creatinine are okay, you've nothing to worry about".  Instead, we watch those numbers over time, to see if they're creeping up.  That's why it's routine to check these tests about every 6 months.  

Changes in thyroid function usually show up within the first year, so he's not likely (it could happen, so we check this too every 6 months) to have the well-known thyroid problems with lithium at this point.  

My recommendation to him: he should have a discussion with a bipolar specialist about the risks he might be facing should he slowly taper off lithium.  Some experts might say he can give that a try if he only had one episode and has done well since.  But there's clearly some risk involved in this.  He needs some "counseling" around this risk just as a woman contemplating pregnancy would get counseling about the risks to her child from taking lithium -- i.e. this is a specialist's area, and getting a second or even third opinion would be fine (as, unfortunately, we don't have enough data to go on for folks like this, so he could easily get two or even three different opinions).  Hope that helps. 

Dr. Phelps