Comparative trial of propranolol and practolol in hyperthyroidism.

Abstract

1 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.

Comparative trial of atenolol and propranolol in hyperthyroidism.

“…Using a similar experimental design, it has been shown previously that propranolol (Shanks et al, 1969;Nelson & McDevitt, 1975) and practolol (Nelson & McDevitt, 1975) are effective in controlling the peripheral manifestations of hyperthyroidism. This present study confirms the efficacy of propranolol and indicates that atenolol, a cardioselective ,6- t Observer could not choose between atenolol and propranolol in four subjects.…”

The assessment of beta‐adrenoceptor blocking drugs in man.

“…On this basis, it was found that a significant relationship between dose and effect could be obtained by drugs without partial agonist activity but not by those with this property (Turner, 1974) and the latter drugs were thought to be unlikely to be effective in this disease situation. However, Carruthers, Ghosal, McDevitt, Nelson & Shanks (1974) showed that, with a modified exercise test, a significant dose-response relationship could be obtained in hyperthyroid patients with practolol (a drug with partial agonist activity) and subsequently practolol was shown to be almost as effective as propranolol in the clinical management of this type of patient (Nelson & McDevitt, 1975). Since ,B-adrenoceptor blocking drugs are competitive inhibitors, it is desirable to investigate their effects in the presence of increased adrenergic activity.…”

Adrenergic beta‐receptor blockade in hyperthyroidism.

“…It is one thing to show an objective reduction in pulse rate, finger tremor and stare and quite another to demonstrate that the administration of the drug actually benefits the patient. For instance, in one double blind trial patients preferred placebo to oxprenolol (Gibberd & Staffurth, 1973) and in the paper by Nelson & McDevitt in the current issue (Nelson & McDevitt, 1975) there was a significant clinical improvement for both propranolol and practolol, yet patient preference for either drug over placebo did not achieve statistical significance. A study of the effect of propranolol on the central manifestations of anxiety and on skin conductance in patients with hyperthyroidism showed that skin conductance significantly decreased following administration of the drug, yet no change in levels of anxiety were found (Ramsay, Greer & Bagley, 1973).…”

“…Similarly oxprenolol has either produced no benefit in hyperthyroid subjects (Gibberd & Staffurth, 1973;Ramsay, 1974) or its administration has been shown to be inferior to that of propranolol (Pimstone, 1969;Tumer & Hill, 1968). Two other adrenergic (-receptor blocking drugs, pindolol and practolol, have been demonstrated to reduce the heart rate in hyperthyroidism, but again not to the same extent as propranolol (Bricaire & Pandos, 1971;Arbab & Tumer, 1971;Nelson & McDevitt, 1975).…”