β-Adrenoreceptor Blockade and Pituitary Hormone Levels

Abstract

Propranolol withdrawal is characterized by a potentially dangerous rebound 'increase in adrenergic activity, which is exaggerated in the presence of hyperthyroidism (Ross, Lewis & Henderson, 1979, Lancet, i, 875). Hyperthyroidism itself results in features suggesting increased adrenergic activity. We have investigated the possibility that changes in thyroid hormone activity could contribute to the propranolol-withdrawal syndrome.