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Page: Prevention
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Preventive strategies include dietary modifications and sometimes also taking drugs with the goal of reducing excretory load on the kidneys:
* Drinking enough water to make 2 to 2.5 liters of urine per day.
* Aquaretics
* A diet low in protein, nitrogen and sodium intake.
* Restriction of oxalate-rich foods and maintainance of an adequate intake of dietary calcium. There is equivocal evidence that calcium supplements increase the risk of stone formation, though calcium citrate appears to carry the lowest, if any, risk.
* Taking drugs such as thiazides, potassium citrate, magnesium citrate and allopurinol, depending on the cause of stone formation.
* Depending on the stone formation disease, vitamin B-6 and orthophosphate supplements may be helpful, although these treatments are generally reserved for those with Hyperoxaluria. Cellulose supplements have also shown potential for reducing kidney stones caused by hypercalciuria (excessive urinary calcium) although today other means are generally used as cellulose therapy is associated with significant side effects.
Certain foods may increase the risk of stones: spinach, rhubarb, chocolate, peanuts, cocoa, tomato juice, grapefruit juice, apple juice, soft drinks (which are acidic and contain phosphorus), and berries, due to high levels of oxalate/ oxalic acid. In the United States, the South has the highest incidence of kidney stones, since it is a region where apple juice consumption is very common. Other drinks are associated with decreased risk of stones, including wine, lemonade and orange juice, the latter two of which are rich in citrate, a stone inhibitor.
Although it has been claimed that the diuretic effects of alcohol can result in dehydration, which is important for kidney stones sufferers to avoid, there are no conclusive data demonstrating any cause and effect regarding kidney stones. However, some have theorized that frequent and binge drinkers create situations that set up dehydration, (alcohol consumption, hangovers, and poor sleep and stress habits). In this view, it is not the alcohol that creates a kidney stone but it is the alcohol drinker's associated behavior that sets it up.
One of the recognized medical therapies for prevention of stones is thiazides, a class of drugs usually thought of as diuretic. These drugs prevent stones through an effect independent of their diuretic properties: they reduce urinary calcium excretion. Nonetheless, their diuretic property does not preclude their efficacy as stone preventive. Sodium restiction is necessary for clinical effect of thiazides, as sodium excess promotes calcium excretion. Though some have said that the effect probably fades after two years or so of therapy (tachyphylaxis), in fact it is only randomized controlled trials lasting 2 years or more that show the effect; there is really no good evidence from studies of calcium metabolism that the thiazide effect does not last indefinitely. Thiazides are the medical therapy of choice for most cases of hypercalciuria (excessive urinary calcium) but may not be suitable for all calcium stone formers; just those with high urinary calcium levels.
Allopurinol (Zyloprim) is another drug with proven benefits in some calcium kidney stone formers. Allopurinol interferes with the liver's production of uric acid. Hyperuricosuria, too much uric acid in the urine, is a risk factor for calcium stones. Allopurinol reduces calcium stone formation in such patients. The drug is also used in patients with gout or hyperuricemia, but hyperuricosuria is not the critical feature of uric acid stones. Uric acid stones are more often caused by low urine pH. Even relatively high uric acid excretion will not be associated with uric acid stone formation if the urine pH is alkaline. Therefore prevention of uric acid stones relies on alkalinization of the urine with citrate. Allopurinol is reserved for patients in whom alkalinization is difficult. For patients with increased uric acid levels and calcium stones, alloprinol is one of the few treatments that has been shown in double-blinded placebo controlled studies to actually reduce kidney stone recurrences.[citation needed] Dosage is adjusted to maintain a reduced urinary excretion of uric acid. Serum uric acid level at or below 6 mg/dL is often the goal of the drug's use in patients with gout or hyperuricemia.
Potassium citrate is also used in kidney stone prevention. This is available as both a tablet and liquid preparation. The medication increases urinary pH (makes it more alkaline), as well as increases the urinary citrate level, which helps reduce calcium oxalate crystal aggregation. Optimal 24 hour urine levels of citrate are thought to be over 320 mg/liter of urine or over 600 mg per day. There are urinary dipsticks available that allow patients to monitor and measure urinary pH so patients can optimize their urinary citrate level.
Though caffeine does acutely increase urinary calcium excretion, several independent epidemiologic studies have shown that coffee intake overall is protective for stones.
Measurements of food oxalate content have been difficult and issues remain about the proportion of oxalate that is bio-available, versus a proportion that is not absorbed by the intestine. Oxalate-rich foods are usually restricted to some degree, particularly in patients with high urinary oxalate levels, but no randomized controlled trial of oxalate restriction has been performed to test that hypothesis.
For those patients interested in optimizing their kidney stone prevention options, it's essential to have a 24 hour urine test performed. This should be done with the patient on his or her regular diet and activities. The results can then be analyzed for abnormalities and appropriate treatment given.
Though not a "cure", ease can sometimes be found during "mild" pain by walking (if possible), preferably in cold air.
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Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
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