Less serious side effects of the generic Zocor medication, include stomach pain, bloating, heartburn and gas, nausea, constipation or diarrhea. As noted above, any muscle, flu or dark-urine symptoms should be immediately reported to your personal physician. Emergency medical help should be sought if you develop an allergic reaction in any form. It is best to stop taking Zocor when any side effects happen and talk to your local doctor.