When I first started to take lithium, I wanted to calculate my peak serum concentration using my 12-hour sample value. I knew it was going to be a very rough estimation, but for me, doing the calculation made me feel less anxious about toxicity.
My plan was to use the exponential decay formula 1 to find the peak concentration (assuming the peak occurred around five hours). I wanted to find out, given I knew my serum creatinine levels, what my approximate lithium half-life was. I went looking for data in the lithium pharmacokinetic literature to figure this out.Continue reading