Patiromer sorbitex calcium, which consists of patiromer, a nonabsorbed cation-exchange polymer, and a calcium-sorbitol counterion, is used for the removal of excess potassium.1, 3, 5, 7
Patiromer sorbitex calcium is used in the treatment of hyperkalemia.1 Patiromer has been shown to decrease elevated serum potassium concentrations and to reduce the recurrence of hyperkalemia in patients with chronic kidney disease who are receiving drugs that inhibit the renin-angiotensin-aldosterone system.1, 3 Because of the delayed onset of action of patiromer, the drug is not used as an emergency treatment for life-threatening hyperkalemia.1
Efficacy of patiromer was established in a 2-part single-blind study that consisted of a 4-week single-group treatment phase followed by an 8-week, randomized, placebo-controlled withdrawal phase.1, 3 Patients with stage 3 or 4 chronic kidney disease who were hyperkalemic with serum potassium concentrations of 5.1 to less than 6.5 mEq/L and who were receiving stable dosages of at least one drug that inhibits the renin-angiotensin-aldosterone system (i.e., angiotensin-converting enzyme [ACE] inhibitor, angiotensin II receptor antagonist, aldosterone antagonist) were included in the study.1, 3 The mean patient age was 64 years and most patients were male (58%) and Caucasian (98%); approximately 97% of patients had hypertension, 57% had type 2 diabetes mellitus, and 42% had heart failure.1, 3
In the initial phase of the study, 243 patients received patiromer.1, 3 Initial dosage of the drug was based on baseline serum potassium concentration; patients with mild or moderate-to-severe hyperkalemia (baseline serum potassium concentration of 5.1 to less than 5.5 mEq/L or 5.5 to less than 6.5 mEq/L, respectively) received an initial patiromer dosage of 8.4 or 16.8 g daily, respectively, in 2 divided doses.1, 3 Dosage was adjusted based on serum potassium concentration on day 3 and at weeks 1, 2, and 3 to achieve and maintain concentrations in the target range of 3.8 to less than 5.1 mEq/L.1, 3 The mean patiromer dosage was 13 or 21 g daily in patients with mild or moderate-to-severe hyperkalemia, respectively.1, 3 The mean reduction in serum potassium concentration from baseline to week 4 was 1.01 mEq/L; 76% of patients had serum potassium concentrations within the target range at week 4.1, 3
The randomized placebo-controlled withdrawal phase included 107 patients with moderate-to-severe hyperkalemia at study entry whose serum potassium concentration was in the target range at the end of the initial study phase, and who were still receiving drugs that inhibit the renin-angiotensin-aldosterone system.1, 3 Patients randomized to continue patiromer therapy received the same dosage they were receiving at the end of the initial study phase.1, 3 For those who received patiromer, the mean dosage was 21 g daily at the beginning of and during the withdrawal phase.1 The primary end point of the randomized withdrawal phase was change in serum potassium concentration from the start of the withdrawal phase to the earliest visit at which the patient's serum potassium concentration was outside the range of 3.8 to less than 5.5 mEq/L, or to week 4 of the withdrawal phase if the patient's serum potassium concentration remained in range.1, 3 Serum potassium concentration increased by a median of 0.72 mEq/L in patients who were switched to placebo but was unchanged in patients who continued receiving patiromer.1, 3 A greater proportion of patients who received placebo had a serum potassium concentration of 5.1 mEq/L or greater (91 versus 43%) or 5.5 mEq/L or greater (60 versus 15%) at any time during the withdrawal phase compared with those who received patiromer.1, 3
Efficacy of patiromer in reducing serum potassium concentration is maintained with continued use.1, 5 In a phase 2, open-label, dose-ranging study in 304 hyperkalemic patients with chronic kidney disease and type 2 diabetes mellitus who were receiving drugs that inhibit the renin-angiotensin-aldosterone system, the effect of patiromer on serum potassium concentration was maintained during continued therapy for periods of up to 52 weeks.1, 5 The mean patiromer dosage during the study was 14 g daily in patients with a baseline serum potassium concentration of greater than 5 to 5.5 mEq/L who received an initial dosage of 8.4 g daily in 2 divided doses and was 20 g daily in those with a baseline serum potassium concentration of greater than 5.5 to 6 mEq/L who received an initial dosage of 16.8 g daily in 2 divided doses.1, 5
Patiromer sorbitex calcium should be administered at least 3 hours before or 3 hours after other oral drugs.1 (See Drug Interactions: Effects on GI Absorption of Drugs.)
Patiromer is administered orally without regard to food.1 Patiromer should not be heated (e.g., in a microwave) or added to heated foods or liquids.1
Patiromer should not be taken in its dry form.1 The powder should be mixed with water immediately prior to administration to form an oral suspension.1 The entire contents of the packet(s) containing patiromer should be emptied into a glass or cup containing 40 mL of water.1 The mixture should be stirred and then an additional 40 mL of water should be added to the suspension. 1 The suspension should again be stirred thoroughly and more water may be added to achieve the desired consistency.1 The suspension should be administered immediately after preparation.1 If powder remains in the glass after initial administration, more water should be added and the mixture should be stirred and then administered immediately; this should be repeated, as needed, until the entire dose is administered.1
Dosage of patiromer sorbitex calcium is expressed in terms of patiromer.1
The recommended initial adult dosage of patiromer is 8.4 g once daily.1 Serum potassium concentration should be monitored, and the dosage of patiromer may be increased (in 8.4-g increments at intervals of 1 week or longer, up to a maximum dosage of 25.2 g once daily) or reduced based on the serum potassium concentration and desired target range.1
Dosage adjustments are not necessary in patients with renal impairment.1
Patiromer is contraindicated in patients with known hypersensitivity to the drug or to any ingredient in the formulation.1
Worsening of GI Motility Disorders
Patients with a history of bowel obstruction or major GI surgery, severe GI disorders, or swallowing disorders were excluded from clinical studies evaluating patiromer.1 Use of patiromer should be avoided in patients with severe constipation, bowel obstruction, or fecal impaction, including abnormal postoperative bowel motility disorders, because the drug may not be effective and may worsen GI conditions.1
Hypomagnesemia was reported in 5.3% of patients receiving patiromer in clinical studies.1 Patiromer binds to magnesium in the colon, which can lead to hypomagnesemia.1 Serum magnesium concentrations should be monitored in patients receiving patiromer, and magnesium supplementation should be considered in those with low serum magnesium concentrations.1
Patiromer is not expected to cause fetal harm when administered to pregnant women because the drug is not absorbed systemically following oral administration.1
Breast-feeding is not expected to result in risk to infants of patiromer-treated women because the drug is not absorbed systemically following oral administration.1
Safety and efficacy of patiromer have not been established in pediatric patients.1
In clinical studies of patiromer, 60% of patients receiving the drug were 65 years of age or older, while 20% were 75 years of age or older.1 No overall differences in efficacy were observed between geriatric patients and younger adults.1 However, adverse GI effects were reported more frequently in those 65 years of age or older compared with younger patients.1
In clinical studies of patiromer, 93% of patients receiving the drug had chronic kidney disease.1 No dosage adjustments are necessary in patients with renal impairment.1
Adverse effects reported in 2% or more of patients receiving patiromer include constipation,1, 3 hypomagnesemia,1, 3 diarrhea,1, 3 nausea,1, 3 abdominal discomfort,1 and flatulence.1
Effects on GI Absorption of Drugs
In vitro binding studies have shown that patiromer binds to approximately 50% of the oral drugs tested; in clinical interaction studies, concomitant oral administration with patiromer altered the bioavailability of some of these drugs.1, 10 Clinically meaningful in vitro binding (i.e., 30% or more) was not observed between patiromer and allopurinol, amoxicillin, apixaban, aspirin, atorvastatin, cephalexin, digoxin, glipizide, lisinopril, phenytoin, riboflavin, rivaroxaban, spironolactone, or valsartan.1, 10 Although clinically meaningful in vitro binding was observed between patiromer and amlodipine, cinacalcet, clopidogrel, furosemide, lithium, metoprolol, trimethoprim, verapamil, and warfarin, studies in healthy individuals indicated that systemic exposure to these drugs was not affected by concomitant oral administration with patiromer.1, 10 Decreased systemic exposure to ciprofloxacin, levothyroxine, and metformin was observed when these oral drugs were administered concomitantly with patiromer but not when the administration times were separated by 3 hours.1, 10 Since binding of patiromer to other concomitantly administered oral drugs could reduce GI absorption of the drugs and result in loss of efficacy when administration times are close to those of patiromer, other oral agents should be administered at least 3 hours before or 3 hours following administration of patiromer.1
Patiromer sorbitex calcium, which consists of patiromer, a nonabsorbed cation-exchange polymer, and a calcium-sorbitol counterion, is used for the removal of excess potassium.1, 3, 5, 7 The drug increases fecal potassium excretion via binding of potassium in the lumen of the GI tract, which decreases the concentration of free potassium in the GI lumen and, consequently, reduces serum potassium concentrations.1 Animal studies indicate that orally administered patiromer is not absorbed systemically and is excreted in feces.1, 6
In an open-label study in patients with chronic kidney disease and hyperkalemia (mean baseline serum potassium concentration of 5.9 mEq/L), serum potassium concentrations were reduced by 0.2 and 0.8 mEq/L at 7 and 48 hours, respectively, following initiation of therapy with patiromer (16.8 g daily in divided doses for 2 days); potassium concentrations remained stable for 24 hours after the last dose and then began to increase.1, 7 Following twice-daily dosing, maximum (steady-state) effects on serum potassium concentration are attained in approximately 7-14 days.8
In healthy individuals, patiromer produced a dose-dependent increase in fecal potassium excretion with a corresponding dose-dependent decrease in urinary potassium excretion, resulting in no change in serum potassium concentrations, when administered at dosages up to 50.4 g daily in 3 divided doses for 8 days.1 Substantial increases in mean daily fecal potassium excretion with concomitant decreases in mean daily urinary potassium excretion also were observed in healthy individuals receiving patiromer 25.2 g daily for 6 days; fecal and urinary potassium excretion were similar whether the drug was administered as a single daily dose or in 2 or 3 divided doses daily.1 Mean patiromer dosage and effects of the drug on serum potassium concentration are similar whether patiromer is administered with or without food.1
Importance of informing patients who are taking other oral drugs to administer these drugs at least 3 hours before or 3 hours after administration of patiromer.1
Importance of informing patients that patiromer may be administered without regard to food and that patients should adhere to their prescribed diets.1
Importance of preparing each dose immediately before administration according to the manufacturer's instructions.1 Importance of advising patients that patiromer should not be heated (e.g., in a microwave) or added to heated foods or liquids and that the drug should not be taken in its dry form.1
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.1
Importance of informing patients of other important precautionary information.1 (See Cautions.)
Additional Information
Overview® (see Users Guide). For additional information on this drug until a more detailed monograph is developed and published, the manufacturer's labeling should be consulted. It is essential that the manufacturer's labeling be consulted for more detailed information on usual cautions, precautions, contraindications, potential drug interactions, laboratory test interferences, and acute toxicity.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
AHFS® Drug Information. © Copyright, 1959-2025, Selected Revisions November 12, 2018. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
1. Relypsa, Inc. Veltassa® (patiromer) powder for oral suspension prescribing information. Redwood City, CA; 2018 May.
3. Weir MR, Bakris GL, Bushinsky DA et al. Patiromer in patients with kidney disease and hyperkalemia receiving RAAS inhibitors. N Engl J Med . 2015; 372:211-21. [PubMed 25415805]
4. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number205739Orig1s000: Summary review. From FDA website. [Web]
5. Bakris GL, Pitt B, Weir MR et al. Effect of patiromer on serum potassium level in patients with hyperkalemia and diabetic kidney disease: the AMETHYST-DN randomized clinical trial. JAMA . 2015; 314:151-61. [PubMed 26172895]
6. Li L, Harrison SD, Cope MJ et al. Mechanism of action and pharmacology of patiromer, a nonabsorbed cross-linked polymer that lowers serum potassium concentration in patients with hyperkalemia. J Cardiovasc Pharmacol Ther . 2016; [PubMedCentral][PubMed 26856345]
7. Bushinsky DA, Williams GH, Pitt B et al. Patiromer induces rapid and sustained potassium lowering in patients with chronic kidney disease and hyperkalemia. Kidney Int . 2015; 88:1427-1433. [PubMedCentral][PubMed 26376130]
8. US Food and Drug Administration. Center for Drug Evaluation and Research. Application number205739Orig1s000: Clinical pharmacology and biopharmaceutics review(s). From FDA website. [Web]
10. Lesko LJ, Offman E, Brew CT et al. Evaluation of the Potential for Drug Interactions With Patiromer in Healthy Volunteers. J Cardiovasc Pharmacol Ther . 2017; 22:434-446. [PubMed 28585859]