Ex vivo effects of nifedipine, nisoldipine and nitrendipine on filterability of red blood cells from healthy volunteers.

In a balanced, randomised and double-blind trial, the effects of single oral dose of nifedipine, nitrendipine and nisoldipine were compared with placebo in eight healthy volunteers. Red cell filterability, measured with a gravity driven filtration technique, was not significantly altered by any of the three calcium antagonists compared with placebo, when RBCs were filtered within 2 h of venepuncture. Storage of RBCs for 24 h at 25 degrees C, however, significantly reduced RBC filterability compared with 2 h (P less than 0.05), but the reduction after nifedipine and nitrendipine was significantly (P less than 0.05) less than after placebo. The above results demonstrate an effect of calcium antagonists on filterability of stored RBCs.