Nishida Y et al. – This study suggested that hematological adverse effects and electrolyte imbalance are greater with angiotensin II type I receptor blocker (ARB) monotherapy than with calcium channel blocker (CCB) monotherapy.

• Authros used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2011, to identify cohorts of new ARB users (n = 601) and propensity–score matched new CCB users (n = 601), with concomitant mild to moderate hypertension and type 2 diabetes mellitus.
• They used a multivariate–adjusted regression model to adjust for differences between ARB and CCB users, and compared laboratory parameters including serum levels of triglyceride (TG), total cholesterol (TC), non–fasting blood glucose, hemoglobin A1c (HbA1c), sodium, potassium, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma–glutamyltransferase (GGT), hemoglobin and hematocrit, and white blood cell (WBC), red blood cell (RBC) and platelet (PLT) counts up to 12 months after the start of ARB or CCB monotherapy.

• Authors found a significant reduction of serum TC, HbA1c, hemoglobin and hematocrit and RBC count and a significant increase of serum potassium in ARB users, and a reduction of serum TC and hemoglobin in CCB users, from the baseline period to the exposure period.
• The reductions of RBC count, hemoglobin and hematocrit in ARB users were significantly greater than those in CCB users.
• The increase of serum potassium in ARB users was significantly greater than that in CCB users.