Formulations and methods for direct sodium removal in patients having heart failure and/or severe renal dysfunction

1. An infusate regimen for use in removing excess sodium and fluid from a patient, the infusate regimen comprising:

a first direct sodium removal (“DSR”) infusate formulated to be administered by infusion into, and removal from, a peritoneal cavity of a patient, the first DSR infusate having a first osmolality in which an aqueous solution contains a sodium concentration equal to or less than 35 meq/L and at least one of 0.5 to 50 grams of dextrose per 100 ml of aqueous solution, 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution, or 0.5 to 50 grams of a high molecular weight biocompatible polymer having an average molecular weight greater than 10,000 Daltons per 100 ml of aqueous solution, or any combination thereof.

2. The infusate regimen of claim 1 , further comprising:

a second DSR infusate formulated to be administered by infusion into, and removal from, the peritoneal cavity of the patient, the second DSR infusate having a second osmolality in which an aqueous solution contains a sodium concentration equal to or less than 35 meq/L and at least one of zero to 50 grams of dextrose per 100 ml of aqueous solution, 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution, or 0.5 to 50 grams of a high molecular weight biocompatible polymer having an average molecular weight greater than 10,000 Daltons per 100 ml of aqueous solution, or any combination thereof.

3. The infusate regimen of claim 2 , wherein the second osmolality is different than the first osmolality.

4. The infusate regimen of claim 2 , wherein the second DSR infusate has an osmolality and sodium concentration selected to induce a shallow sodium gradient between the patient's blood serum sodium level and the second DSR infusate when instilled into the peritoneal cavity during a second dwell period.

5. The infusate regimen of claim 2 , wherein the each of the first DSR infusate and the second DSR infusate are formulated to be instilled into a patient's peritoneal cavity in an amount between 0.25 liter and 2.0 liter per DSR session.

6. The infusate regimen of claim 1 , wherein the first DSR infusate has an osmolality and sodium concentration selected to induce a steep sodium gradient between a patient's blood serum sodium level and the first DSR infusate when instilled into the peritoneal cavity during a first dwell period.

7. The infusate regimen of claim 1 , wherein the first DSR infusate is sodium-free.

8. The infusate regimen of claim 1 , wherein the first DSR infusate is essentially sodium-free.

9. The infusate regimen of claim 1 , wherein the first DSR infusate comprises 0.5 to 50 grams of dextrose per 100 ml of aqueous solution and 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution.

10. The infusate regimen of claim 9 , wherein the first DSR infusate further comprises water.

11. The infusate regimen of claim 9 , wherein the first DSR infusate comprises 10 grams of dextrose per 100 ml.

12. The infusate regimen of claim 9 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat fluid overload of the patient.

13. The infusate regimen of claim 9 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat heart failure of the patient.

14. The infusate regimen of claim 9 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat severe renal dysfunction of the patient.

15. The infusate regimen of claim 1 , wherein the first DSR infusate consists essentially of 0.5 to 50 grams of dextrose per 100 ml of aqueous solution, 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution, and water.

16. The infusate regime of claim 14 , wherein the 0.5 to 50 grams of dextrose per 100 ml of aqueous solution is 10 grams of dextrose per 100 ml of aqueous solution.

17. The infusate regime of claim 14 , wherein the 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution is 15 to 30 weight percent icodextrin.

18. The infusate regime of claim 14 , wherein the 0.5 to 50 grams of dextrose per 100 ml of aqueous solution is 5 to 10 weight percent dextrose and the 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution is 15 to 30 weight percent icodextrin.

19. The infusate regimen of claim 15 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat fluid overload of the patient.

20. The infusate regimen of claim 15 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat heart failure of the patient.

21. The infusate regimen of claim 15 , wherein the first DSR infusate is configured to be administered to the patient in need thereof to treat severe renal dysfunction of the patient.

22. The infusate regimen of claim 1 , wherein the first DSR infusate removes excess sodium to cause a reduction in fluid overload in the patient while maintaining a serum sodium level substantially unchanged.

23. The infusate regimen of claim 1 , wherein the first DSR infusate is configured to be administered by infusion into the peritoneal cavity of the patient for a dwell period of at least two hours.

24. A method of removing excess sodium and fluid from a patient, the method comprising:

administering a first DSR infusate having no or low sodium and a first osmolality into a peritoneal cavity of a patient to induce sodium and osmotic ultrafiltrate to accumulate with the first DSR infusate in the peritoneal cavity during a first dwell period, wherein the first DSR infusate has the first osmolality in which an aqueous solution contains a sodium concentration equal to or less than 35 meq/L and 0.5 to 50 grams of dextrose per 100 ml of aqueous solution and 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution; and

removing the first DSR infusate, sodium and osmotic ultrafiltrate from the peritoneal cavity of the patient after the first dwell period.

25. The method of claim 24 , further comprising:

administering a second DSR infusate having no or low sodium and a second osmolality into the peritoneal cavity of the patient to induce sodium and osmotic ultrafiltrate to accumulate with the second DSR infusate in the peritoneal cavity during a second dwell period, wherein the second DSR infusate has the second osmolality in which an aqueous solution contains a sodium concentration equal to or less than 35 meq/L and 0.5 to 50 grams of dextrose per 100 ml of aqueous solution and 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution; and

removing the second DSR infusate, sodium and osmotic ultrafiltrate from the peritoneal cavity of the patient after the second dwell period.

26. The method of claim 25 , wherein the first and second DSR infusates are administered to the patient in need thereof for treating heart failure.

27. The method of claim 25 , wherein administering each of the first DSR infusate and the second DSR infusate comprises instilling into the patient's peritoneal cavity an amount between 0.25 liter and 2.0 liter of fluid per DSR session.

28. The method of claim 24 , wherein the first DSR infusate consists essentially of 0.5 to 50 grams of dextrose per 100 ml of aqueous solution, 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution, and water.

29. The method of claim 28 , wherein the 0.5 to 50 grams of dextrose per 100 ml of aqueous solution is 10 grams of dextrose per 100 ml of aqueous solution.

30. The method of claim 28 , wherein the 0.5 to 50 grams of dextrose per 100 ml of aqueous solution is 5 to 10 weight percent dextrose and the 0.5 to 50 grams of icodextrin per 100 ml of aqueous solution is 15 to 30 weight percent icodextrin.