I currently take 1050mg of lithium (tablets) at night. I have been on this dose for years, but in the past 6 months I've been getting terrible headaches, and before I knew about the negative interactions, I would take ibuprofen for the headaches and experience what I now know were side-effects of nausea, irritability, etc.

What kind of painkillers can I take for headaches and/or muscle aches that won't interact badly with lithium?