Medicine Name: Twinblok Trio Tablet ER. Composition: Chlorthalidone (12.5mg) + Metoprolol Succinate (50mg) + Cilnidipine (10mg). Side Effects: Nausea Diarrhea Vomiting Constipation Headache Dizziness Flushing sense of warmth in the face ears neck and trunk Weakness Slow heart rate Decreased blood pressure Cold extremities Numbness of extremity Decreased potassium level in blood Increased blood lipid level Decreased sodium level in blood Decreased magnesium level in blood Increased uric acid level in blood.