- Electrolytes: Patients may be entered into the study, if the investigator's opinion is that any electrolyte disorders, including potassium <3.4 mEq/L, calcium <8.4 mg/dL, or magnesium <1.2 mEq/L, may be appropriately managed and stabilized by the time of the laboratory evaluation on the baseline day in Period 1. If electrolytes have not been stabilized during this time, the patient will be discontinued from the study.