Propranolol counters thrombocytopenia in patients with cirrhosis by altering splenic hemodynamics.
Propranolol contracts arteries supplying the spleen so, in theory at least, it potentially modifies hypersplenic symptoms, such as thrombocytopenia.
To test this hypothesis, researchers from Kurume University School of Medicine, and Iwao Hospital, Hita, Japan, enrolled 19 patients with cirrhosis and thrombocytopenia. Ten patients received propranolol and the remainder placebo. The propranolol dose reduced heart rate by between 20 and 25 percent.
Placebo did not significantly alter either splenic artery hemodynamics or platelet count. In contrast, propranolol increased both intra-splenic artery pulsatility index and platelet count. The average intra-splenic artery pulsatility index increased from 1.10 to 1.24 in the propranolol arm. Propranolol also increased the average platelet count from 4.5 to 6.1 x 104 per mm3. Both these differences reached statistical significance.