Today, we’re taking a brief look at the most commonly prescribed medications for kidney stone prevention, why doctors choose them, and the medical conditions that can make them necessary. Here’s how each medication works, the conditions it treats, and how lifestyle changes can enhance its effects.
Medications are prescribed when people cannot use diet alone to lower their stone risk. Although diet may not always totally prevent stones for every person, it will ALWAYS help, and in many cases you will go on a lower dose of the medication as a result. You should continue following the Kidney Stone Diet® regardless of whether you must take meds.
1/5 Potassium Citrate
How It Works: Potassium citrate alkalizes the urine (raising its pH), making it less acidic, and raises urinary citrate levels. Citrate binds with calcium in the urine, reducing its ability to form stones. Think of citrate as a shield that envelopes calcium so none of those other evil crystals can connect to her (I always see calcium as a “she,” but I am not sure why). If you don’t have enough citrate, you cannot fully protect the calcium hanging around your urine, and oxalate and phosphate are just itching to find her and make a kidney stone. So, another great reason to eat your fruits and veggies, folks!
Best For: Patients with uric acid or calcium oxalate stones, particularly those with low urinary citrate or high urine acidity.
Common Medical Conditions:
- Metabolic Acidosis: Conditions like renal tubular acidosis lower citrate levels and create an acidic environment that encourages stone formation.
- Chronic Diarrhea or Inflammatory Bowel Disease (IBD): Conditions like Crohn’s disease or ulcerative colitis can lead to dehydration and more acidic urine.
- Diabetes and Metabolic Syndrome: These conditions often reduce urinary citrate and make urine more acidic, increasing the risk of stone formation.
Additional Risk Factors: Diets high in meat protein (anything that swims, flies, or runs) can acidify urine and lower urinary citrate. Not eating enough fruits and veggies can also cause low citrate levels in the urine.
Side note. You may be unable to use potassium citrate because of kidney or heart issues. Sometimes, your doctor may prescribe sodium bicarb to increase urine pH and citrate. Read about that here.
2/5 Thiazide Diuretics
(e.g., Hydrochlorothiazide, Chlorthalidone)
How It Works: Thiazides reduce urinary calcium by helping the kidneys reabsorb more calcium back into the bloodstream, lowering the calcium available to form stones.
Best for: Patients with calcium oxalate and calcium phosphate stones, particularly those with high urinary calcium levels (hypercalciuria).
Common Medical Conditions:
- Primary Hyperparathyroidism: Overactive parathyroid glands increase blood and urinary calcium, raising stone risk.
- Vitamin D Disorders: Excessive vitamin D can increase calcium absorption and urinary calcium levels, as can too little vitamin D.
- Osteoporosis: Bone breakdown releases calcium, increasing blood and urinary calcium levels.
- Absorptive Hypercalciuria: A genetic condition that causes the intestines to absorb too much calcium. This is why stones can run in families.
Sodium Reduction: Lowering sodium intake is especially beneficial with thiazides because high sodium increases urinary calcium. A low-sodium diet (less than 2,300 mg per day- ideally 1,500) enhances the effectiveness of thiazides, as it reduces calcium excretion and stone risk.
3/5 Allopurinol
How It Works: Allopurinol lowers uric acid production by inhibiting an enzyme involved in uric acid synthesis, decreasing blood and urinary uric acid levels. This is especially useful for preventing uric acid stones.
Best for: Patients with uric acid or calcium oxalate stones and high urinary uric acid levels that they cannot control through diet.
Common Medical Conditions:
- Gout: A metabolic disorder associated with elevated uric acid, which can lead to gout and uric acid stones.
- Obesity and Metabolic Syndrome: Both can elevate uric acid levels, raising the risk of uric acid and calcium oxalate stones.
- Type 2 Diabetes: Often leads to acidic urine, increasing the risk of uric acid stones.
- Specific Cancer Treatments: Chemotherapy and other treatments that cause rapid cell turnover raise uric acid levels.
- Long-term steroid use: Steriods can cause excess uric acid and also high urine calcium.
Additional Risk Factors: Diets high in purines (found in red meat, seafood, and alcohol) can elevate uric acid levels, as can overeating some veggies. Overeating sugar can also increase uric acid production in the body.
4/5 Magnesium Supplements
How It Works: Magnesium binds with oxalate in the intestines, reducing oxalate absorption and lowering urinary oxalate levels. This reduces the oxalate available to combine with calcium, preventing calcium oxalate stones.
Best for: patients with calcium oxalate stones and low urinary magnesium.
Common Medical Conditions:
- Chronic Diarrhea or Malabsorption Disorders: Conditions like celiac disease, ulcerative colitis, Crohn’s, or short bowel syndrome may limit magnesium absorption.
- Diabetes: Poorly controlled diabetes can lead to urinary loss of magnesium.
- Chronic Alcoholism- This leads to magnesium deficiency through poor intake and increased urinary excretion.
Additional Risk Factors: Low intake of magnesium-rich foods (like green leafy vegetables, nuts, and whole grains) can contribute to low urinary magnesium.
5/5 Phosphate Supplements
(e.g., Sodium Phosphate, Potassium Phosphate)
How It Works: Phosphate binds with calcium in the intestines, reducing calcium absorption into the bloodstream and lowering urinary calcium. This can help prevent calcium-based stones.
Best for: Patients with calcium oxalate or calcium phosphate stones who absorb too much calcium from their intestines (absorptive hypercalciuria).
Common Medical Conditions:
- Genetic Predisposition: Absorptive hypercalciuria can be hereditary, causing increased calcium absorption from the gut.
- Hypervitaminosis D: Excess vitamin D or conditions like sarcoidosis can increase calcium absorption.
- Hyperparathyroidism: Overactive parathyroid glands can indirectly increase intestinal calcium absorption.
Additional Risk Factors: Excessive dietary calcium or supplements without balance can increase urinary calcium in susceptible individuals.
Each medication targets specific underlying issues that contribute to stone formation. By understanding these medications and conditions, you can work with your healthcare provider to create a prevention plan tailored to your unique needs.
Your friend and advocate,
Jill
Disclaimer: Please get in touch with your doctor or pharmacist if you have questions about these medications. They will know what is best for you and your current medical conditions. I will not comment on any emails as I am the diet expert, not the medication expert.
Leave a Reply