Medicaments that depend on a combination of SGLT 2 inhibitors and antihypertensive drugs and which are useful in the treatment of diseases involving at least hypertension or diabetes mellitus as a risk factor of cardiovascular events, as well as methods of treating the diseases are provided. Since the present invention exhibits a superior hypotensive action that cannot be attained by any single antihypertensive drugs, the conventional problems associated with the use of two or more antihypertensive drugs in order to lower the blood pressure to the desired level can be solved. In addition, the present invention shows a marked therapeutic efficacy in diabetes mellitus, a disease associated with diabetes mellitus, or complications of diabetes mellitus, in particular, diabetic nephropathy. As a further advantage, the present invention is also useful for the treatment of diseases involving lowered renal function.