Bendroflumethiazide is a thiazide diuretic typically used to treat an excess buildup of fluid in the body. Thiazide diuretics work directly on the kidneys by helping them more effectively eliminate the excess fluid through urine. Bendroflumethiazide also is used to help manage hypertension, although exactly how it works on this condition was unknown as of early 2011. When used to treat hypertension, bendroflumethiazide is often combined with the beta blocker medication nadolol.
Excess fluid buildup, or edema, has many potential causes, from something as mild as consuming too much sodium to as severe as congestive heart failure. Edema occurs when the capillaries become too full and start to leak fluid, which in turn signals the kidneys to compensate by retaining more sodium and water. This leads to more fluid running through the body, causing the capillaries to leak even more and creating swelling in the surrounding tissues. Without medical intervention, this cycle continues, putting pressure on the blood vessels, decreasing circulation of blood throughout the body and putting excess strain on the heart. The excess swelling also puts pressure on the skin, increasing the risk of tears and infection.
Bendroflumethiazide works inside the kidneys by inhibiting sodium-chloride reabsorption from the distal convoluted tubules inside the kidneys. These tubules help control the levels of salts such as sodium, potassium and calcium in the bloodstream. Reducing the amount of these salts helps the kidneys more easily draw out excess water from the bloodstream, which decreases the overall volume of fluid in the veins and arteries, reducing pressure and helping the heart pump more adequately.
Patients might be required to increase their potassium intake through either foods or dietary supplements, because bendroflumethiazide reduces the body's potassium levels. The side effects of bendroflumethiazide typically occur during the initial stage of therapy, and they include dizziness, blurred vision, itchiness, headache and extreme fatigue. Generally, the side effects decrease after taking the medication for a while. Other medications, such as corticosteroids, narcotic pain relievers, muscle relaxers and other high blood pressure drugs, can increase the risk of side effects.
Bendroflumethiazide should be used with caution by pregnant women, nursing women or patients who have liver disease, kidney disease, gout or low levels of potassium or sodium. Those who have urinary problems or an allergy to sulfonamides should not take bendroflumethiazide. Other medications, such as non-steroidal anti-inflammatory drugs or medicines used to treat diabetes might decrease the effectiveness of bendroflumethiazide.