['hyperkalemia']
['sodium zirconium cyclosilicate (zs) 10g', 'sodium zirconium cyclosilicate (zs) 5g', 'sodium zirconium cyclosilicate (zs) 10g', 'placebo']

        Inclusion Criteria:

          -  Provision of informed consent prior to any study specific procedures

          -  Female and male patients aged ≥18 and ≤ 90 years

          -  Two consecutive i-STAT potassium values, measured 60-minutes (± 10 minutes) apart,
             both ≥ 5.1 mmol/l and measured within 1 day of the first ZS dose on 48-hour open-label
             initial phase 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 for the duration of the study and for 3 months
             after the last dose of ZS/matching placebo to prevent pregnancy.

        Exclusion Criteria:

          -  Involvement in the planning and/or conduct of the study

          -  Participation in another clinical study with an investigational product during the
             last 3 months

          -  Pseudohyperkalemia signs and symptoms

          -  Patients treated with lactulose, xifaxan (rifaximin) or other non-absorbed antibiotics
             for hyperammonemia within 7 days prior to the first dose of study drug

          -  Patients treated with resins,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 subjects' tasks associated with the protocol

          -  Female patients who are pregnant, lactating, or planning to become pregnant

          -  Patients with 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

          -  Patients with cardiac arrhythmias that require immediate treatment

          -  Patients on dialysis

          -  Patients who are blood donors should not donate blood during the study and for 3
             months following their last dose of ZS
      