The effects of pindolol and prazosin on hand blood flow in patients with cold extremities and on treatment with beta-blockers.

Hand blood flow and subjective sensitivity to cold were studied in nine hypertensive patients on treatment with beta-blockers. All patients complained of cold extremities. Neither hand blood flow nor sensitivity to cold changed after addition of prazosin, a well known vasodilator to the original beta-blocker. After changing to a beta-blocker with a high degree of intrinsic sympathomimetic activity (pindolol), hand blood flow increased and sensitivity to cold decreased in all patients, except one.