Comparative trial of propranolol and practolol in hyperthyroidism.

The possible role of practolol in the management of hyperthyroidism has been studied by comparing it with propranolol. 2. In a double-blind cross-over trial, propranolol (40 mg), practolol (120 mg) and a placebo four times daily for one week were compared in twenty-one hyperthyroid patients by sequential analysis. 3. Judged by their effect on the symptoms and signs of thyrotoxicosis, both propranolol and practolol were significantly better than the placebo but no clear distinction could be made between the two active compounds. 4. Propranolol and practolol reduced heart rate by 24 and 17% respectively compared with placebo. 5. Patients generally preferred propranolol or practolol to placebo but this preference did not achieve significance with either drug. 6. Only in its effect on heart rate was practolol significantly inferior to propranolol, and it would appear to be a useful alternative to propranolol in the management of the peripheral manifestations of hyperthyroidism.