Effects of propranolol and metoprolol on the peripheral circulation.

The effects of single doses of propranolol and metoprolol on skin temperature and skin and muscle blood flow were compared in 10 normal subjects and four patients with essential hypertension. In normal subjects the mean skin temperature fell by 1.30 +/- 0.62 degrees C 90 minutes after 80 mg propranolol and 0.15 +/- 0.05 degrees C after 100 mg metoprolol. Skin blood flow and resting muscle blood flow were not affected by metoprolol but fell significantly after propranolol. Both drugs reduced post-exercise muscle hyperaemia, propranolol by more than metoprolol. Similar changes were seen in the hypertensive patients. Propranolol should be used with care in patients with known vascular disease.