What medication is a small, round, white pill that's plain on one side, scored on the other with K & 18 on the scored side?

Nearest match we found is a white, round pill with imprint "K 18," which has been identified as Oxycodone hydrochloride 5 mg. It is used to treat pain.

Tuesday, October 30 2012
Source: http://www.drugs.com/imprints/k-18-15461.html