Please select the eligibility criteria that correspond to the clinical trial below.
Title: Efficacy of Sodium Polystyrene Sulfonate in the Treatment of Hyperkaliemia in Ambulatory Pre-dialysis Outpatients : a Randomized Triple-blind Placebo-controlled Trial
Brief Summary: The purpose of this trial is to determine if sodium polystyrene sulfonate (SPS) is an effective treatment of mild hyperkalemia in chronic kidney disease patients followed at a pre-dialysis or nephrology outpatient clinic. Subjects will be randomized to one of two treatment arms: 30 g of placebo or SPS to be taken orally once daily for seven days. The change in serum potassium levels will be compared in both treatment groups. The proportion of subjects attaining normokalemia (3.5 to 5.0 mmol/L) after seven days of treatment will also be compared. Finally, side effects will be reported for each treatment arm.


Options:
A: Inclusion Criteria:

* Males and Females, age at least 18 years
* ESRD treated with thrice-weekly HD for ≥ 6 months.
* At least two measured pre-dialysis serum \[K\] ≥ 5.5 mEq/L or one \[K\] ≥ 6.0 mEq/L noted over the past three months
* Current use of dialysate with potassium concentration ≤ 2 mEq/L
* Typical consumption of at least two meals per day
* Have received customary dietary instruction over prior month
* Considered by the treating physician(s) to be in otherwise stable clinical condition.
* If patient is of childbearing potential, he/she will be willing to avoid pregnancy during the study using an acceptable birth control method.

Exclusion Criteria:

* Not considered by the treating physician(s) to be adherent with recommended dialysis schedule and prescribed medications
* Life expectancy \< 3 months
* Dialysis-dependent for less than 6 months
* Non-elective hospitalization in prior 3 months
* Currently prescription of oral potassium supplements
* In the prior 3 months, therapy with oral potassium-lowering medication
* Underlying severe gastrointestinal disorders, including history of ischemic bowel.
* Corrected serum calcium concentration \> 10.5 mg/dL in prior three months
* Anticipated kidney transplant within the next 3 months
* Prisoners or others who are involuntarily incarcerated or detained
* Pregnant, breastfeeding, or considering pregnancy.
* Participation in a clinical trial of an experimental treatment within the past 30 days
B: Inclusion Criteria:

* Provision of written informed consent.
* Over 18 years of age.
* GFR between 40-60 ml/min as estimated by the CKD-EPI equation. After screening two additional GFR values of between 40-60ml/min must be repeated within 24 hours before inclusion is allowed.
* S-K between 5.0 - 6.0 mmol/l (inclusive) during Study Day 0.
* Ability to have repeated blood draws or effective venous catheterization.
* Women of child bearing potential must be practicing a highly effective method of birth control.

Exclusion Criteria:

* Pseudohyperkalemia such as excessive fist clinching hemolyzed blood specimen, severe leukocytosis or thrombocytosis.
* Subjects treated with lactulose, xifaxan or other non-absorbed antibiotics for hyperammonemia within the last 7 days.
* Subjects treated with resins (such as sevelamer acetate, calcium acetate or calcium carbonate, lanthanum carbonate, Sodium polystyrene sulfonate (SPS; e.g. Kayexalate®) within the last 7 days.
* Subjects with a life expectancy of less than 3 months.
* Subjects who are HIV positive.
* Subjects who are severely physically or mentally incapacitated and who in the opinion of investigator are unable to perform the subjects' tasks associated with the protocol.
* Women who are pregnant, lactating, or planning to become pregnant.
* Subjects with Ketoacidosis/Acidemia.
* Cancer within the last 5 years (other than successfully treated basal or squamous cell carcinoma of the skin, carcinoma in situ of the cervix or early stage prostate cancer).
* Presence of any condition which, in the opinion of the investigator, places the subject at undue risk or potentially jeopardizes the quality of the data to be generated.
* Known hypersensitivity or previous anaphylaxis to Zirconium Silicate or to components thereof.
* Subjects who have cardiac arrhythmias that require immediate treatment.
* Subjects with ECG changes associated with hyperkalemia.
* Subjects with acute kidney injury.
C: Inclusion Criteria:

* Aged 18 years and over
* Outpatients followed at the pre-dialysis or nephrology clinics of Maisonneuve-Rosemont Hospital
* Subjects who have taken SPS in the past 7 days: serum potassium level measured for their regular followup of 4.5 to 5.5 mmol/L, inclusive, and serum potassium level of 5.0 to 5.9 mmol/L, inclusive, after a one week washout period
* Subjects who have not taken SPS in the past 7 days: serum potassium levels measured for their regular followup and on the day of randomisation of 5.0 to 5.9, inclusive

Exclusion Criteria:

* Subjects with a contraindication to SPS : known hypersensitivity to the product, history of obstructive bowel disease, patients at high risk of obstructive bowel disease
* Subjects unable of giving informed consent
* Subjects with severe or symptomatic hyperkalemia requiring a treatment
* Subjects on dialysis (hemodialysis or peritoneal dialysis)
* Women who are pregnant or breastfeeding
* Subjects who have had a change in the dosage of insulin in the past week, if this change represents more than 10% of the daily total dose or more than 5 units
* Subjects who stopped, started or changed the dosage of an angiotensin converting enzyme inhibitor, an angiotensin II receptor blocker or aliskiren in the past 60 days
* Subjects who stopped, started or changed the dosage of another medication affecting serum potassium levels in the past 30 days
* Subjects who have had an episode of decompensated heart failure in the past 30 days
* Subjects currently enrolled on another research protocol
* Subjects who are lactose intolerant
D: Inclusion Criteria:

* Provision of informed consent prior to any study specific procedures.
* Patients aged ≥18. For patients aged \<20 years, a written informed consent should be obtained from the patient and his or her legally acceptable representative.
* Two consecutive i-STAT potassium values, measured 60 (± 10) minutes apart, both values should be ≥ 5.1 mmol/L and ≤ 6.5 mmol/L and measured within 1 day before the first dose of study drug on Study Day 1.
* Ability to have repeated blood draws or effective venous catheterization.
* Female patients must be 1 year post-menopausal, surgically sterile, or using an acceptable method of contraception (an acceptable method of contraception is defined as a barrier method in conjunction with a spermicide) for the duration of the study (from the time they sign consent) and for 3 months after the last dose of ZS/matching placebo to prevent pregnancy. In addition, oral contraceptives, approved contraceptive implant, long-term injectable contraception, intrauterine device, or tubal ligation are allowed. Oral contraception alone is not acceptable; additional barrier methods in conjunction with spermicide must be used.

Exclusion Criteria:

* Involvement in the planning and/or conduct of the study (applies to both AstraZeneca staff and/or staff at the study site)
* Cause or symptoms of pseudohyperkalemia, such as

  1. hemolyzed blood specimen due to excessive fist clenching to make veins prominent
  2. hemolyzed blood specimen due to difficult or traumatic venepuncture
  3. history of severe leukocytosis or thrombocytosis
* Patients treated with lactulose, rifaximin, or other non-absorbed antibiotics for hyperammonemia within 7 days prior to first dose of study drug on Study Day 1
* Patients treated with resins (such as sevelamer hydrochloride, sodium polystyrene sulfonate \[SPS; e.g. Kayexalate®\] or calcium polystyrene sulfonate \[CPS\]), calcium acetate, calcium carbonate, or lanthanum carbonate, within 7 days prior to the first dose of study drug
* Patients with a life expectancy of less than 3 months
* Patients who are severely physically or mentally incapacitated and who, in the opinion of investigator, are unable to perform the patients' tasks associated with the protocol
* Female patients who are pregnant, lactating, or planning to become pregnant
* Patients who have an active or history of diabetic ketoacidosis
* Presence of any condition which, in the opinion of the investigator, places the patient at undue risk or potentially jeopardizes the quality of the data to be generated
* Known hypersensitivity or previous anaphylaxis to ZS or to components thereof
* Treatment with a drug or device within the last 30 days that has not received regulatory approval at the time of study entry
* Patients with cardiac arrhythmias that require immediate treatment
* Patients on dialysis

Answer: C