Effect of phosphate binders upon TSH and l-thyroxine dose in patients on thyroid replacement

@article{Diskin2006EffectOP,
  title={Effect of phosphate binders upon TSH and l-thyroxine dose in patients on thyroid replacement},
  author={Charles J Diskin and Thomas J. Stokes and Linda M. Dansby and Lautrec Radcliff and Thomas B. Carter},
  journal={International Urology and Nephrology},
  year={2006},
  volume={39},
  pages={599-602}
}
BackgroundWhile calcium carbonate is known to interfere with the gastrointestinal absorption of levothyroxine, we hypothesized that other phosphate binders would also bind to levothyroxine and decrease bioavailability of levothyroxine in dialysis patients.MethodsThe records of 1,566 patients on hemodialysis who were being treated by the Hypertension, Nephrology, Dialysis, and Transplantation Center (the regional renal referral center for Eastern Alabama, USA) were evaluated. The type of… 

l-thyroxine malabsorption due to calcium carbonate impairs blood pressure, total cholesterolemia, and fasting glycemia

Monitoring of hypothyroid patients who ingest medications that decrease l-thyroxine absorption should not be restricted to solely measuring serum TSH.

Undertreated hypothyroidism due to calcium or iron supplementation corrected by oral liquid levothyroxine

Liquid levothyroxine is resistant to the sequestration by calcium or iron, and the high rate of thyroid-stimulating hormone normalization already at the first check (6–8 weeks) should avoid frequent adjustments in lev Timothyroxine doses and assays of Thyroid- Stimulating hormone, with consequent financial savings.

Absorption of levothyroxine when coadministered with various calcium formulations.

Hypothyroid patients should be cautioned to take their levothyroxine well-separated from all of these calcium formulations, as the effect of calcium is modest compared with some other medications previously studied.

Phosphate binders as a cause of hypothyroidism in dialysis patients: practical indications from a review of the literature

This case differs from other reports on lower TSH at diagnosis, underlining the need for awareness of the importance of early diagnosis, and supports close monitoring of TSH.

Oral liquid levothyroxine solves the problem of tablet levothyroxine malabsorption due to concomitant intake of multiple drugs

LIQ overcomes the concurrent interference exerted by the ingestion of multiple interfering drugs (ID) and permits patients to reach target TSH levels within 8 weeks.

Serum thyrotropin levels following levothyroxine administration at breakfast.

Levothyroxine administration with breakfast could be an alternative regimen for patients who have adherence difficulties due to the need for delaying intake, and is more likely to cause variability in the TSH level, meaning the patient should be followed more closely.

The clinical utility of free thyroxine in oral levothyroxine absorption testing.

FT4 and TT4 correlated highly, even in patients who were severely hypothyroid; FT4 may be used interchangeably with TT4 as a qualitative assessment of suspected malabsorption using an oral LT4 absorption test.

Clinical relevancy of the levothyroxine-continuous enteral nutrition interaction.

Differences between those who developed subclinical or overt hypothyroidism versus those who remained euthyrotic could not be explained by age, weight, levothyroxine dose, type of EN formula, or amount of EN received.

Concurrent Milk Ingestion Decreases Absorption of Levothyroxine.

This is the first study to demonstrate that concurrent cow's milk ingestion reduces oral levothyroxine absorption, supporting previous literature showing the interference of elemental calcium and food with thyroid hormone absorption.

Drug Interactions with Levothyroxine Therapy in Patients with Hypothyroidism: Observational Study in General Practice

Clinicians should carefully consider adjusting levothyroxine therapy in presence of concomitant drugs, such as proton-pump inhibitors, which may reduce lev Timothyroxine bioavailability.

References

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Both calcium carbonate and calcium acetate are similarly effective as phosphate binder in predialysis patients and the carbonate group required four fold greater doses of calcium that acetate group, which has less hypercalcemic effect than calciumcarbonate.

Effect of calcium carbonate on the absorption of levothyroxine.

This study of 20 patients receiving long-term levothyroxine replacement therapy indicates that calcium carbonate reduces T(4) absorption and increases serum thyrotropin levels.

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Calcium acetate controls serum phosphorus and calcium-phosphate product more effectively than sevelamer hydrochloride and should remain the treatment of choice for hyperphosphatemia in hemodialysis patients, cost-benefit analysis indicates.

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Cal calcium acetate, not previously used for medical purposes, is approximately as efficient as aluminum carbonate gel and more efficient as a phosphorus binder than other currently used calcium salts.

Evidence for interference with the intestinal absorption of levothyroxine sodium by aluminum hydroxide.

A patient with hypothyroidism who was euthyroid on a fixed-dosage, long-term maintenance regimen of levothyroxine sodium developed persistently elevated serum thyrotropin levels while receiving an aluminum hydroxide-containing antacid, indicating that aluminum Hydroxide may interfere with the bioavailability of thyroxine.

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Antacids used to decrease phosphorus absorption in patients with renal failure may be toxic. To find more efficient or less toxic binders, a three-part study was conducted. First, theoretical

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A 64-year-old female on haemodialysis thrice weekly started with sevelamer for hyperphosphataemia and noticed that her urine production stopped within 24 h after taking the first seVELamer capsule, and increased after withdrawal.

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Treatment of children with CKD with sevelamer and calcium acetate provides similar phosphorus level control and a marked decrease in lipid levels and lower rate of hypercalcemia may augment the long-term benefit of seVELamer.