Effect of long-term salbutamol treatment on renin-aldosterone system in twin pregnancy
Lammintausta, R.; Erkkola, R.
Acta Obstetricia et Gynecologica Scandinavica 58(5): 447-451
1979
ISSN/ISBN: 0001-6349 PMID: 394562 Document Number: 148713
Plasma renin activity (PRA), urinary aldosterone excretion (dU-Aldo), urinary electrolytes (dU-Na, dU-K) and plasma progesterone were studied weekly in 22 women with twin pregnancies for 3 wk while on salbutamol therapy (= 8 mg 3 .times. daily) in hospital. Patients (15) in this group were treated with diuretics for an average of 6 wk and the therapy continued. All the patients except 3 were treated with depot-formed oxyprogesterone during the study. As an additional control group 10 twin pregnant women without any drug therapies were studied. The mean level of PRA in twin pregnancy before .beta.-sympathomimetics was equal to that of the same phase (the 32nd wk) of normal pregnancy. On the 2nd day of the treatment the PRA level was 3-fold (P < 0.001) and later on 2-fold (P < 0.05) when compared with the level before the treatment. Before .beta.-sympathomimetics the mean level of dU-Aldo was in twin pregnancy higher than in normal pregnancy (P < 0.01). During the treatment dU-Aldo increased within a week and a positive correlation between PRA and dU-Aldo was found (P < 0.01). A decrease in dU-Na and an increase in dU-K were found (P < 0.05), corresponding to the increased effect of aldosterone. The increased levels of progesterone and aldosterone in twin pregnancy agree with earlier suggestions concerning the importance of progesterone in the secretion of aldosterone during pregnancy. The stimulating effect of .beta.-sympathomimetics leads to a renin-mediated secondary aldosteronism and tends to cause hypokalemia.