Doctors monitor blood pressure---the force the blood exerts on the walls of the blood vessels---to help determine overall health. High blood pressure, a condition known as hypertension, describes a condition in which the systolic measures 140 mmHg or higher and the diastolic measures 90 mmHg or higher, according to the American Heart Association. Although making healthy lifestyle choices can help reduce high blood pressure, many patients also require one of several types of medications. Because all medications have a possibility of side effects and complications, the risk must be measured against the benefit for each patient.
Irregular Heartbeats
Doctors commonly prescribe diuretics, also known as water pills, to treat high blood pressure. Diuretics induce the kidneys to increase the production of urine by inhibiting the reabsorption of sodium in various places throughout the tubes in the kidneys. Because diuretics help the body expel excess fluids and salts, they reduce the volume of blood therefore reducing blood pressure. However, they can also reduce the level of other salts such as potassium, leading to hypokalemia---a low level of potassium. A drop in potassium can cause abnormal heart rhythms, especially in patients who also suffer from heart disease, according to MedlinePlus.
Sudden Drop in Blood Pressure
Successfully treating high blood pressure often takes time and trying several different combinations of medications. Some medications commonly used to treat high blood pressure, such as beta blockers and alpha blockers, can cause a sudden drop in blood pressure. A change of 20 mmHg in blood pressure can deprive the brain of blood and oxygen and result in dizziness and fainting, according to MayoClinic.com. Diuretic medications can reduce the volume of blood too much, leading to hypovolemic shock, a potentially life-threatening condition.
Impotence
Many blood pressure medications can interfere with the ability to obtain or maintain an erection, a condition known as impotence. An erection requires a precise sequence of events involving nerve signals between the brain, spinal cord and penis, along with muscle coordination and a response of blood in the veins and arteries in and around the erectile tissues in the penis, as described by the National Kidney and Urologic Diseases Information Clearinghouse. Anything that interrupts this series of events can result in impotence. Blood pressure medications most likely to cause impotence include thiazide diuretics such as chlorthiazide and beta blocker medications such as propanolol, according to MedlinePlus.
