This orange, oval pill imprinted with GSI500 is a 12 HR ranolazine 500 MG Extended Release Tablet [Ranexa], per the NIH.
Ranexa is a human prescription drug. The active pharmaceutical ingredient is ranolazine and is classified as, "Anti-anginal [EPC]."
This pill is made by a total of 2 firms: (1) Gilead Sciences, Inc., and (2) Cardinal Health
There are 4 other orange pills that with a similar imprint: "GSI500". They may be a different dosage of the same drug or a different drug entirely.