Gout is a type of arthritis. It is caused by raised levels of uric acid in the bloodstream (hyperuricaemia) which crystallise and are deposited in the joint tissues of the body. These crystals cause a local reaction leading to inflammation which in turn causes enormous pain to the sufferer. The joints most commonly affected are the smaller joints of the hands and feet, but other joints can also be involved.
The onset of gout can be sudden, classically appearing during the night or early morning. The affected area becomes swollen and painful, to the point where even a sheet resting on the joint, e.g. the toe, can be too painful to bear
Pre-dialysis & dialysis patients
Gout occasionally occurs in people with poor kidney function not yet on dialysis and in dialysis patients. Uric acid builds up in the blood because the damaged kidneys are unable to remove it. Also, many of these patients take water tablets (diuretics) which can cause gout themselves. These patients are more often affected by a similar condition called pseudogout, where the inflammation is caused by the deposition of calcium pyrophosphate crystals. This can be the result of renal bone disease due to kidney failure but may be due to other causes. Pseudogout has similar symptoms to gout but tends to affect large or medium sized joints such as knees, hips, wrists and shoulders.
Transplant patients taking cyclosporin (Neoral) are affected by gout particularly if they are taking water tablets (diuretics) as well. The cyclosporin reduces the kidney’s ability to clear uric acid from the blood.
1. Treatment of acute gout The aim of treatment for the acute phase of gout is to reduce inflammation and pain in the joints. The traditional first line of attack is with nonsteroidal anti- inflammatory drugs (NSAIDS) such as sulindac, diclofenac, ibuprofen, or naproxen. However, these drugs are often not given to kidney patients because they can cause a decline in kidney function and fluid retention. In dialysis patients, preservation of kidney function by avoiding NSAIDs is less important but the drugs would still be used with caution. The main drug therapy for acute gout in kidney patients is colchicine. It does not share the problems of NSAIDs but the dose may need to be adjusted carefully depending on kidney function and side-effects experienced (nausea, vomiting, diarrhoea & abdominal pain are common). Colchicine is an effective treatment but it may take around 24 hours for the full benefit to be seen.
2. Long term treatment Some people will need to be given drugs to prevent them getting further attacks of acute gout. The drug used is called allopurinol and it works by reducing the levels of uric acid in the blood. The drug needs to be taken regularly to make an attack less likely. Allopurinol is started after the acute phase has been treated. Starting sooner can worsen or prolong the acute attack. The most common side-effect of allopurinol is a skin rash, which should be reported to your doctor who may need to reduce the dosage or stop it temporarily.