Cortel Trio Tablet belongs to the group of medications called antihypertensives. It contains a combination of telmisartan, hydrochlorothiazide, and Amlodipine, which controls blood pressure when a single medication is ineffective. It is primarily used for the treatment of hypertension. Hypertension (high blood pressure) is a medical condition in which blood exerts a force on the artery walls (blood vessels), resulting in heart disease, irregular heartbeat, and other problems. Before taking this medication, let your physician know if you have hypersensitivity (allergic reactions) to any of the ingredients of this medication. Report to your doctor immediately if you have anuria (kidney failure that causes less urine production) and diabetes. It is not recommended for people with hypotension (low blood pressure), liver and kidney disease, heart failure, electrolytes, and metabolic disorders. This medication is not intended to be used during the second and third trimesters of pregnancy, as it reduces fetal renal function and causes harmful effects on the developing fetus. The common side effects of Cortel Trio Tablet are sleepiness, ankle swelling, nausea, headache, flushing, dizziness, fatigue (tiredness), palpitations, stomach upset, peripheral edema, and mood changes. Notify your doctor immediately if you experience any persistent or troubling side effects.