Telma H belongs to the category of ARB drugs, which stands for angiotensin receptor blockers. Angiotensin 1 receptors work for contraction and relaxation of smooth muscle that is present in the arteries. This potent drug, Telma H, binds to the angiotensin-1 receptors causing the arteries in the heart to relax, and therefore, reducing blood pressure. Hydrochlorothiazide is a diuretic drug that helps to eliminate excess water and making your muscles and arteries more relaxed. It allows the unrestricted flow of blood, which works to make your heart pump the blood productively. It efficiently works to bring down the blood pressure level to the normal range.