Effects of piretanide, bumetanide and frusemide on electrolyte and urate excretion in normal subjects.

1. The pharmacological actions of a new short acting loop diuretic were investigated in nine healthy male subjects and compared with those of frusemide and bumetanide. Subjects received 6 mg piretanide/day, 40 mg frusemide/day or 1 mg bumetanide/day for a period of 1 week. 2. Comparison of effects following the first dose administered showed that 6 mg piretanide is of similar potency to 40 mg frusemide in terms of diuresis, natriuresis and kaliuresis but is less potent than 1 mg bumetanide. 3. All three diuretics caused a decrease in urate excretion and a rise in serum uric acid. 4. Piretanide was well tolerated. Further investigation is required to ascertain what clinical advantage it offers over frusemide and bumetanide.

An evaluation of the luteinizing hormone releasing hormone (LH-RH) test in patients with secondary amenorrhoea.

An analysis of the gonadotrophin response to an intravenous injection of LH-RH (50 mug) has been undertaken in 41 patients with secondary amenorrhoea. Thirty-five of the patients were free of any recognizable pathology to account for their amenorrhoea and apparently had a dysfunction of the hypothalamic-pituitary axis. In these patients, the gonadotrophin response to LH-RH was highly variable. There was in general a correlation between baseline plasma LH or FSH levels and their respective increments. There was no correlation, however, between basal oestrogen levels and gonadotrophin increments except in the case of those patients whose basal levels of plasma FSH were higher than those of LH and in those patients whose body weight was less than the ideal for the population. It appears that the gonadotrophin response to a single injection of LH-RH in the majority of patients with secondary amenorrhoea of unknown origin is too variable to be of use either as a diagnostic or prognostic tool.

A comparative trial of a new, fast-release iron capsule ("Eryfer") and a slow-release tablet ('Ferro-Gradumet') in iron-deficiency anaemia.

Sixty hospitalised patients receiving treatment for tuberculosis, diabetes or chronic bronchitis and who had iron-deficiency anaemia (Hb levels less than 12.5g./100 ml.) were entered in a between-patient comparative study of a new, fast-release iron capsule ('Eryfer') and a standard slow-release iron tablet ('Ferro-Gradumet'). Patients were allocated to either drug at random and recived either 2 capsules (100 mg. elemental iron) or 1 tablet (105 mg. elemental iron) daily for 30 days. Haemoglobin levels and packed cell volume were measured before and at the end of the trial period. The results, analysed in 57 patients (28 on 'Eryfer' and 29 on the slow-release iron) indicate that treatment with 'Eryfer' produced a significantly more predictable response in haemoglobin regeneration, the response being dependent on the initial haemoglobin level. Both treatments, however, produced a highly significant increase in haemoglobin levels in the patients (mean increas: 'Eryfer' 1.09 g. and slow-release iron 0.76 g.). No side-effects were recorded with either treatment.