What is gout?
Gout is caused by an excess of uric acid in the blood (hyperuricaemia) which forms crystals and these uric acid crystals are then deposited in the joints and tissues. Uric acid is a produced as a result of metabolism of purines, which are found in high protein foods like meat and fish. Excess uric acid is normally removed by the kidneys, however, if too much is produced or the kidneys cannot dispose of it sufficiently uric acid build up in the blood.
Deposition of uric acid crystals in joints causes painful swelling of the joints and loss of joint mobility and affects mainly the big toe but can affect other joints, including joints of the hands, feet, knee and elbow. There are several risk factors for gout including genetic predisposition, obesity, excess alcohol intake and high meat consumption.
Uricosuric treatments for gout
There are specific medications for treating gout, which are known as a uricosuric drug that helps the removal of uric acid from the blood and this reduces the risk of uric acid crystals being deposited in the joints. Uricosuric drugs like probenecid work by acting directly on the kidneys to increase excretion of uric acid by the kidneys and this limits the amount of uric acid in the blood. Less uric acid reduces crystal formation, which allows the crystals already in the joints to dissolve and the pain and swelling to be reduced.
Other gout treatments
Allopurinol blocks an enzyme involved in uric acid synthesis and this reduces the amount of uric acid production and reduces levels of uric acid in the blood. Allopurinol is also used for prevention of kidney stone formation and uric acid crystals under the skin called skin tophi.
Colchicine blocks the action of inflammatory cells and is used to treat gout to help reduce inflammation associated with uric acid crystals in the joints.