Hello As you mentioned in the query that your doctor prescribe coversyl 4 mg i.e. perindopril . However, you didn t mention the name of the disease for which this drug advised . Usually this is indicated for hypertension and congestive heart failure ( CHF). You are feeling tiredness, nausea, lightheaded stomach ,as all these are most common side effects of coversyl but need not to worry . Since you are taking this drug for 7 days( week ) , so it will adjust in your body after 15 days ( approximately ) . Low sugar level is not a cause of concern because coversyl never decreases blood sugar level and this will maintained withing time by homoestasis . The important point is the treatment for this drug advised . When such patient visit I advise my patient to take a combination of rabeprazole+aceclofenac ( until and unless contraindicated ) . So this is a prescription medicine , consult your treating physician and take a prescription and you will get relief in all these symptoms , as mentioned in the query. Hope this will be useful for you. Good luck.