Patented in 1949, Hydralazine was actually discovered while scientists at Ciba (a Swiss chemical company) were looking for a treatment for malaria. Hydralazine is a medication used to treat high blood pressure and heart failure. This includes high blood pressure in pregnancy and very high blood pressure resulting in symptoms. Basically, Hydralazine works by relaxing the muscles in your blood vessels to help them dilate (widen). This lowers blood pressure and allows blood to flow more easily through your veins and arteries. As for this medication’s side effects, they include headache and fast heart rate. Bear in mind that Hydralazine is not recommended in people with coronary artery disease or in those with rheumatic heart disease that affects the mitral valve. However, in those with kidney disease a low dose is recommended.