Hi & Welcome. Chlorthalidone is a thiazide diuretic ( water pill ) that helps prevent your body from absorbing too much salt, which can cause fluid retention. It is commonly prescribed in the treatment of fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or kidney disorders. It is also used alone or in combination with other drugs like Metoprolol or Losartan to treat resistant high blood pressure (hypertension). It is found to be as effective and safe as Losartan or Metoprolol after kidney transplantation. So, in view of the above continue taking it as prescribed by your cardiologist. Best regards.