Lithium, fatigue, athletic performance, dehydration
Lithium, fatigue, athletic performance, dehydration
Archive post May 27, 2008
This is the 3rd and last of the articles I wrote related to BD. Over the years I got a lot of comments and questions on this one on wordpress.com.
Fatigue and muscle weakness are commonly listed as possible side effects of lithium. But as far as I can tell, that’s as far as anyone takes the subject. The causal mechanisms aren’t discussed. Nor are possible management strategies. I had those side effects bad enough to be almost ready to quit lithium when I figured out what was going on. I was then able to eliminate the side effects with a very simple remedy. I am not making suggestions for anyone but this is my story and it may be interesting to those on lithium, their family and friends, and those with patients on lithium.
I began medial treatment for BPDII Dec 2006 with Lamictal, presumably because I was presenting with depression. The Lamictal modified the depression by making me irritable and agitated all the time. Whether this change of mood was due to the drug or the disease wasn’t clear initially. But by summer I’d had enough of agitation and irritability (despite a attempt to mitigate it with Seroquel) and wanted a change.
So I started lithium. We monitored side effects, plasma Li level and kidney function during the ramp up. I had the thirst at first but that went away. Otherwise, all OK.
But when I got to 900mg sustained release daily dose I started to feel fatigued, weak, lethargic, and sluggish. I was sleeping more: 9-10 hours at night plus naps in the day. I had no energy and continuously faced a strong urge to lie down on the couch. My mood was affected: I was unhappy, irritable, and mean. And my athletic performance was dismal. This was very disturbing.
I am a male, early 40’s, and a cyclist. I do long distance cycling and a little bit of racing. I am relatively good; I finished Boston-Montreal-Boston 2006 in 70hr 34min, around the top 25% in an event that attracts cyclists from all over. I finished the 2006 400km Boston Brevet in 15hr 37min first out of 54 riders, 5 min faster than the next finisher. So before I started BPD treatment, I was a decent athlete. And please trust me that I have a good idea of what kind of baseline performance I can expect.
My performance on the bike in Nov and Dec was bad. I felt tired, my legs ached, I was having no fun and I was slow. My performance was off by 30-40% in terms of power*. I was embarrassed when I went out with the buddies. I didn’t enjoy cycling. My ambitions for 2008 seemed questionable.
It seemed like I was facing a choice between lithium and cycling. If so, it was fairly clear that lithium would lose since cycling has done more for my heath and mental well-being than any psychodrug.
Then in early Jan 2008 it started to get better. I was thrilled. I was not back to my previous performance but I was not far off. I had some good fast rides with the troop and things looked well. My shrink, who had no idea what had been causing the fatigue, agreed with me when I said: perhaps it was an initial thing and my body had adapted. But then in Feb the fatigue returned.
In Mar, while I was still feeling bad, I stopped taking lithium for one week to see what would happen. By the end of that week I was significantly improved, not fully recovered but noticeably better. When I started the lithium again I was back where I was.
I make a note of my weight regularly and the sheet is on the bathroom wall. So it was obvious when my body weight jumped up by 2.5% when I stopped lithium, stayed there for the week and then jumped back down where it was when I resumed taking lithium.
But it was a couple of weeks before a likely explanation dawned on me. My hypothesis was that lithium was causing dehydration and that dehydration was causing my symptoms of fatigue and weakness.
So I started drinking more. I was already drinking a lot relative to typical civilians but I stepped it up. I now drink 4-5liter H2O a day (roughly a pint every 90min) when not exercising. When cycling this goes up to about 0.75 – 1liter/hr depending on temperature and effort. When I get up at night to pee, I drink some more. I felt better already the day after I started drinking like this. The symptoms were gone.
Well, almost. Occasionally I have a day when I feel the side effects again. I attribute it to falling behind on my drinking.
I’ve discussed this with my shrink, who accepts the dehydration theory, and at length with my GP. He has several patients on lithium and explained to me how it affects the kidneys.
Lithium encourages the kidneys to drain clean water out of the blood. Technically, they say that it inhibits the kidneys’ ability to concentrate urine. That’s true but that doesn’t explain the dehydration. Better started: lithium inhibits the kidneys’ ability to concentrate urine AND boosts urination. So, for example, if you are dehydrated and on lithium, you can still pee plenty of pale or clear urine. For an athlete, this is tremendously important to understand.
Like many endurance sportspeople, I was in the habit of estimating hydration by monitoring urine color, volume and frequency. But on lithium this is misleading. As my GP explained, the only thing to go on is the sense of thirst. I make an effort to pay close attention to this. It’s a new habit and not so easy to learn but I think it works.
So that’s the end of my story. However, I’m still rather disappointed that I had to figure this out on my own. My shrink didn’t suspect dehydration as the cause of my symptoms. I found no clue despite hours of searching and reading online. I found mention of fatigue and muscle weakness and I found mention of the kidney effects and the need to drink enough but nothing that connected these – nothing to warn that lithium can cause dehydration that in turn can cause fatigue, muscle weakness, irritability and lethargy.
After I resolved the issue, I searched again armed with better queries and again found no sign that this is an understood problem. My shrink accepted the theory but it seemed new to her. Considering that one of the documented effects of dehydration (2% is enough) is mood disturbance (irritability is often recorded), this seems unreasonable. Aside from the physical symptoms, lithium is causing mood problems in some patients — needlessly.
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* This was estimated from heart rate. Properly prepared (rest, feeding, etc.), I can expect to be able to ride at average 165bpm for an hour. This was down to 130bpm. Taking my sitting heart rate as 55bpm, this indicates about 40% power loss.