Telmeros CL 40mg/12.5mg Tablet includes two medications that help to manage high blood pressure. Telmeros CL 40mg/12.5mg Tablet is a combination of two medications, Telmisartan and chlorthalidone. It is typically used when a single medication is ineffective in managing blood pressure. Telmisartan works by relaxing and broadening your blood vessels, allowing your blood to flow more readily. This lowers your blood pressure. Chlorthalidone is a diuretic (water pill) that increases urine production, reducing blood pressure. Controlling your blood pressure reduces your risk of having a heart attack, stroke, or renal problems. To be successful, the medication must be taken on a regular basis, as prescribed.