HDCN Abstract:  American Soc Hypertension (ASH)  

Leary WP, Reyes AJ

Magnesiuretic potency of twenty-seven oral formulations of diuretics: report on a study series in progress

American Soc Hypertension (ASH)
Am J Hypertens (May) 13:113A 2000

The responses of mean 24-h magnesiuresis (MM) and natriuresis (MN) to single doses of twenty-seven oral formulations of diuretics have thus far been evaluated in sixteen studies, thirteen of which were individually randomized, crossover, double-blind and placebo controlled (pre-treatment MM and MN served as controls in the three open trials).

In each study, 7-19 healthy adults staying in a metabolic unit received one (open studies) or more treatments (on conveniently separated single-treatment days). The study series (n = 198 volunteers) control MM was 4.6 mmol; MN had a study series control value of 161 mmol. Results refer to changes with respect to control MM and MN in each study.

Thiazide-type diuretics: cicletanine (CICL) 50 and 150 mg did not modify (p > 0.05) MM, but they raised (p < 0.05) MN by 26 and 49%; CICL 100 mg, clopamide 5 mg, clorexolone 10 mg, chlorthalidone 100 mg, hydrochlorothiazide (HCTZ) 25 mg (which was tested in two studies), HCTZ 50 mg (which was tested in two studies), and xipamide 5, 10, 20 and 40 mg increased MM between 17 and 87% and MN between 47 and 165%.

Loop diuretics: muzolimine (MUZ; this substance is no longer available) 20, 30 and 40 mg and torasemide (TOR) 2.5, 5 and 10 mg did not change MM (MUZ 20 mg and TOR 2.5 mg did not change MN, whereas MUZ 30 and 40 mg and TOR 5 and 10 mg raised it between 17 and 34%); furosemide (FUR) 80 mg and TOR 20 mg raised MM by 20 and 24% and MN by 86 and 78%.

Potassium-retaining diuretics: amiloride (AMI) 5 and 10 mg did not change MM, but they raised MN by 38 and 66%; spironolactone (SPIR) 100 mg did not change MM nor MN.

Combinations: FUR 40 mg & AMI 5 mg, FUR 80 mg & AMI 10 mg, HCTZ 50 mg & AMI 5 mg, and HCTZ 25 mg & SPIR 100 mg did not modify MM, but they raised MN between 64 and 88%.

Roughly, MM paralleled MN after loop and thiazide-type diuretics. MUZ 20 mg and TOR 2.5 mg, both of which are loop diuretics and are provenly effective once-daily antihypertensive monopharmacotherapies, did not raise MM and were the only formulations tested that qualified as very-low-dose formulations, since they did not increase MN.

© Copyright 2000 American Journal of Hypertension, Ltd. Reproduced with permission from ASH and Elsevier.