A PHARMACOLOGY TEACHING EXERCISE IN DRUG EVALUATION: A COMPARISON OF THE DIURETIC EFFICACY OF CLOREXOLONE, HYDROCHLOROTHIAZIDE AND A PLACEBO IN NORMAL SUBJECTS

In 63 healthy medical students, grouped in 21 randomized blocks, the comparative effects of clorexolone, hydrochlorothiazide and placebo on the quantity of urine excreted and on weight loss were studied. Each subject ingested a single 50-mg. dose of one of the medications. An oral saltloading technique was employed. Measurements were recorded during the four hours following administration. This experiment, which was an integral part of a teaching program in pharmacology, permitted a practical demonstration to medical students of the four fundamental control measures in clinical pharmacology: the comparison with a standard medication and/or a placebo, the random distribution of treatments, the double-blind technique and the statistical analysis of data. In this study hydrochlorothiazide proved to have significantly greater diuretic activity than placebo and clorexolone; the latter medication did not demonstrate effects statistically superior to those of the placebo. A highly significant positive correlation was found to exist between the measurements of urine volume and weight loss.

ETIOLOGICAL FACTORS IN THIAZIDE-INDUCED OR AGGRAVATED DIABETES MELLITUS

Nine patients with diabetes mellitus and three normal controls were treated for one week with hydrochlorothiazide (150 mg. per day), and certain effects on carbohydrate metabolism were observed. Evidence presented in this study confirms the thiazide-induced carbohydrate intolerance. Tests of insulin reserve (serum ILA response to glucose), response to insulin, insulin binding, urinary steroid excretion, serum potassium, serum nonesterified fatty acids, and serum amylase failed to reveal any abnormality related to the carbohydrate intolerance. There was reduction of the whole blood glutathione levels in six of seven subjects. DIABETES 14:132–36, March 1965.

TREATMENT OF CONGESTIVE HEART FAILURE WITH TRIAMTERENE

Triamterene, a newer oral diuretic, was administered to nine hospitalized patients with congestive heart failure for an average of 15 days, and to 22 ambulatory patients for a period of three to 11 months. The daily dosage of triamterene ranged from 50 to 250 mg., but usually 100-200 mg. was administered daily in two divided doses, with or without the addition of 50 mg. of hydrochlorothiazide daily.Triamterene is a safe and effective diuretic at doses of 100-200 mg. daily and no drug tolerance develops with long-term therapy. However, when used alone, it is not as effective as hydrochlorothiazide, but in combination with the latter drug the resultant diuresis is unsurpassed by any other oral diuretic therapy that we have used to date.Triamterene itself does not produce kaliuresis and it blocks thiazide-induced kaliuresis. Serum uric acid levels may rise slightly, but no clinical gout was seen in this study.

SMALL BOWEL ULCERATION ASSOCIATED WITH ENTERIC-COATED POTASSIUM CHLORIDE AND HYDROCHLOROTHIAZIDE

Three cases of intestinal obstruction due to solitary localized ulceration, inflammation and stenosis of the small bowel are described. All three patients had been treated with a pill containing hydrochlorothiazide and an enteric-coated centre of potassium chloride. The occurrence of this lesion in these patients, and in similar cases reported from other centres, suggests that such a combination should not be prescribed.