Is there any otc pills i should avoid since i only have one kidney ?

Yes: You should avoid NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen, naproxen. You should also avoid prescribed NSAIDs such as meloxicam and piroxicam. Also avoid "natural" pills, including vitamin C pills. Megadoses of vitamin C (more than 60mg daily) has been associated with oxalate nephropathy and interstitial nephritis. So just because something's "natural" doesn't mean it's safe

One kidney: with one kidney you should avoid any thing that would damage the kidney. A good example is any NSAID like ibuprofen or aspirin.