Value of Liquid Potassium Magnesium Citrate in Controlling Hypertension
The design will be a randomized sequence of four phases, consisting of KMgCit, potassium citrate, potassium chloride and placebo (microcrystalline cellulose), using cri=ossover design. All four formulations will be delivered in a liquid form, to ensure double blindness. This design should permit us to discern contribution to blood pressure-lowering of individual components of KMgCit. We therefore hope to test the hypothesis that the hypotensive action of the DASH diet is due to the combined effects of potassium, magnesium and alkali.
Placebo will comprise microcrystalline cellulose, equivalent in volume in each sachet as other test products (made by Meta Pharm Development, LLC, St. Louis, MO). During the Placebo Phase, subjects will dissolve the entire content of a sachet in 250 ml water and drink it with breakfast and again with dinner.
Potassium chloride powder, also prepared by Meta Pharm Development, identical in appearance to potassium citrate powder, will contain 20 meq KCl per sachet. During the Potassium Chloride Phase, subjects will dissolve the content of each sachet in 250 ml water and ingest it with breakfast and again with dinner, to deliver 40 meq K (as chloride) per day.
Potassium citrate powder (formerly Urocit®-K powder) is already approved by the F.D.A.; it will soon be marketed by Nova-K, a subsidiary of Meta Pharm Development. For this study, a special sachet formulation containing 20 meq K/sachet will be made for the study by Meta Pharm Development. The contents of a sachet will be added to 250 ml water and drunk with breakfast and dinner, to deliver 40 meq K (as citrate) per day during the Potassium Citrate Phase.
Potassium magnesium citrate will be prepared by mixing potassium citrate, magnesium citrate and/or citric acid by Meta Pharm Development. The content of each sachet will be dissolved in 250 ml water and will be drunk with breakfast and again with dinner during the KMgCit Phase, to deliver 40 meq K, 20 meq Mg and 74 meq citrate per day.
A taste enhancer might be added to improve tolerance of the test medications. Each sachet will be marked by a code, the identity of which will be known only to an independent study monitor. Each sachet will be labeled: Study drug # --; Diet Study in Hypertension; Investigator: W. Vongpatanasin, M.D.
Diet and Other Drugs
Subjects will be maintained on their customary diet throughout the study. If subjects are already on ACE inhibitors or ARB, they will be continued on the medications at the same dose throughout the study.
Subjects with prehypertension or Stage I hypertension, with systolic blood pressure of 120-159 mm and diastolic of 80-99 mm, will be recruited into the trial. They may be adult men or women (> 21 years of age) of any ethnicity. They may be on ACE inhibitor or ARB, but not on spironolactone (aldactone) or any diuretic.