1Twenty-one hyperthyroid patients participated in an 8-week double-blind crossover trial of propranolol and practolol, and the effects of these drugs on the clinical and metabolic features of the disease were studied. 2 Propranolol was marginally more effective than practolol, as measured by the hyperthyroid diagnostic index and anxiety scale. 3 Propranolol produced greater reduction in pulse rate, blood pressure and tremor, whereas practolol caused a greater improvement in eye signs. 4 Propranolol produced a significant reduction in the serum concentration ratio of tri-iodothyronine to thyroxine, compatible with partial inhibition of peripheral deiodination of thyroxine. 5 Adverse reactions occurred more frequently with propranolol than with practolol. 6 In view of the efficacy of practolol, further trials in hyperthyroid patients of newer f,1 -adrenoceptor antagonists, preferably without partial agonist activity, are indicated.

Summary: A retrospective study of thyrotoxic patients treated by subtotal thyroidectomy between 2 and 21 years ago in the north-east of Scotland showed that 20% of the patients could not be identified or traced at the time of the survey. The thyroid status of 40% of patients followed up was abnormal.It is now accepted that radioiodine treatment of thyrotoxicosis is followed by a significant incidence of late onset hypothyroidism, and life-long foliow-up is regarded as obligatory. The findings in this study indicate that similar methods of aftercare are required for surgically treated patients and for all patients receiving thyroxine-replacement therapy.

A comparative study of the outcome of surgical treatment for thyrotoxicosis was carried out in two countries with dissimilar dietary iodine levels. In the area with a high iodine level (Iceland) the prevalence of post-operative hypothyroidism was five times lower, but recurrent hyperthyroidism was five times higher, than in the area with lower iodine levels (northeast Scotland). The total morbidity reached comparable levels in the two samples. The prevalence of positive thyroid antibody tests and serum thyrotrophin levels was lower and the functional capacity of the thyroid remnant higher in the area with the higher dietary iodine intake. The study provides further evidence that there are important regional differences in the prevalence of factors known to influence the response to surgical treatment of thyrotoxicosis which should be taken into account when planning treatment services.