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Types of Stones
Uric Acid Stones
Hyperuricosuria can result from eating an excessive amount of meat, fish or poultry, and almost always can be controlled if the individual changes his diet. For those who find it difficult to change their dietary habits, stone formation can be prevented through use of a drug called allopurinol, which reduces production of uric acid.
Uric acid stones can also be prevented in many cases through useof an alkaline agent that regulates the acidity of the individual's urine, a key factor controlling crystallization of uric acid. Gout, a disorder of purine metabolism associated with arthritis, may also cause hyperuricemia, hyperuricosuria, and uric acid stones. This disorder requires specific drug treatment.
Struvite Stones
Struvite stones are composed of magnesium, phosphate, and ammonium. They can be very difficult stones to treat, because they result from infection of the urinary tract that can recur even after the stones have been removed. This type of stone can fill the entire inside of the kidney, spreading into the smallest passages, blocking drainage of urine, and resulting in severe kidney damage.
Struvite stones occur mainly due to infection with a certain type of bacteria that tends to flourish and invade the kidney following a course of antibiotic therapy. For this reason, the best preventive measure against this type of kidney stone is to be aware of the need to be careful in the use of antibiotics.
One should take them only when the doctor determines that it is absolutely necessary. In recent research, scientists also have found that an agent called acetohydroxamic acid (AHA), an inhibitor of the chemical action caused by the invading bacteria, can be used to effectively retard struvite stone formation.
Hyperparathyroidism
Overactivity of the parathyroid glands (hyperparathyroidism) is also a frequent cause of calcium stone disease. The parathyroids are tiny glands in the neck that produce a hormone that regulates the level of calcium in the blood. When these glands are overactive, too much parathyroid hormone in the system causes bone cells to release calcium that is retained in the blood.
At the same time, abnormally high amounts of calcium also build up in the blood, and eventually the calcium level increases so much that it spills over into the urine where it promotes formation of kidney stones.
Once the physician makes the diagnosis of hyperparathyroidism, future stones from this cause can be prevented through surgical removal of all or part of the abnormal parathyroid gland. In most cases, only one of the glands is enlarged and its removal ends the individual's problem with kidney stones.
Cystine Stones
Another type of stone occurs in individuals with the relatively rare inherited defect of kidney function causing cystinuria. In this disorder, the amino acid cystine overloads the urine where it crystallizes and forms stones. Prevention of cystine stones is difficult, because there is no definitive treatment.
The main therapy is for the individual to drink enough water to dissolve the cystine that escapes into the urine each day. This therapy can be difficult, because cystine is eliminated continuously, and so the individual may be required to drink over a gallon of water every 24 hours. At night, about a third of a gallon of water may be consumed on this regimen, filling the bladder repeatedly and interfering with sleep.
Sometimes when stones cannot be controlled through increased fluid consumption, the drug penicillamine is administered to make the cystine more soluble. This approach is always used cautiously, however, because individuals often have severe allergic reactions to this drug.
Though kidney stones can be very painful, it's important to remember that all tests, surgeries, procedures and medications carry benefits and risks. In order to make an informed decision about the best option for you, be sure to ask your physician to explain the benefits, risks and costs of each option.
Copyright 1995 Health ResponseAbility Systems, Inc.
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