This clinical trial consists of 2 parts, Part A and Part B. Part A consists of a 2-day randomized, double-blind, placebo-controlled corrective phase (CP) and a 28-day randomized, double-blind, placebo-controlled maintenance phase (MP). Part B (open-label extension, OLE) is an open-label, 11-month extension study carried out in participants who come from Part A and meet certain inclusion criteria.
Adults (male or female) aged 18 years and older;
Participants with a serum potassium concentration >5.0 mmol/L and ≤6.5 mmol/L (serum potassium concentration will be measured using the i-STAT portable biochemical analyzer in screening period);
Participants who have negative pregnancy test result at screening and ensure the use of contraception during the trial;
Participants who understand and voluntarily sign the Informed Consent Form.
Participants who have a history of severe drug allergy, or are definitely allergic to the investigational product or its ingredients;
Participants who have pseudohyperkalemia, such as serum potassium increasing caused by hemolysis of blood samples due to improper blood collection methods (such as too tight pressure pulse band banding, too heavy local rubbing, repeated fist clenching-loosening hands), hemolysis of blood samples due to difficulty in venipuncture or trauma, and severe leukocytosis (>50 × 10^9/L) or thrombocytosis (>500 × 10^9/L);
Participants with acute hyperkalemia caused by conditions such as tumor lysis syndrome or hemolysis and so on;
Participants suffering from severe cerebrovascular diseases, such as cerebral infarction or cerebral hemorrhagic disease, with language disorder or unresponsiveness, or severely blocked limb movement;