Menstruation disorders caused by spironolactone (Aldactone). A 51 year old hypertensive woman treat

Fråga: Menstruation disorders caused by spironolactone (Aldactone). A 51 year old hypertensive woman treated with spironolactone 50 mg daily for 6-12 months has noted spotting and increased menstrual bleeding over the summer. Has had a dilatation and curettage. She is on no other medication.

Sammanfattning: In any case, although the cause of spironolactones unpleasant side-effects remains unidentified, the effects of this drug on steroid biosynthesis and androgen action are clear. Dose reduction will usually not relieve these problems.

Svar: The endocrine adverse effects associated with spironolactone use began to be reported soon after the drug´s introduction in the 1960s, and gynecomastia and decreased libido in males and painful breasts and menstrual irregularities in females are relatively common problems. These seem to be dose-related, and for the menstrual irregularities the incidence was 100 per cent at 400 mg/day, but even at 100 mg/day, a 77 per cent incidence was reported (although this was observed in women with some degree of kidney diseases). Time appears to be an important factor in the development of these side effects, since in a study of normal males, none had developed gynecomasytia before 8 weeks but 66 per cent had done so by 24 weeks. All the endocrine complications are reversible and the earlier report of breast carcinoma associated with prolonged administration of spironolactone has not been confirmed by more complete studies.

Although closely related to the corticosteroids, spironolactone does not seem to have cortisone-like effects, and the exact mechanism by which the estrogen-like effects are produced is not known. Spironolactone affects testosterone synthesis in humans, but the resulting changes in circulating testosterone and estradiol do not explain the estrogen-like adverse effects of the drug or therapeutic doses. It has also been suggested that the binding of testosterone and estradiol at the receptor level are altered by spironolactone or that the drug may inhibit estrogen degradation by reducing 17alpha-hydroxylase activity.