Endocrine Abstracts

Introduction: Drospirenone is a synthetic progestin usually found in combination with ethynilestradiol in oral contraceptive formulas. In 2007, this compound was also used in hormonal replacement therapy during menopause. Drospirenone shows antimineralocoricoïd effect due to an analogy of structure with aldosterone. This effect counteracts the estrogen stimulating action of renin–angiotensin–aldosterone (RAA) system, lowering water retention symptoms due to classic oral contaception. On the other hand, primary aldosteronism (PA) accounts for 6% of hypertension. Screening of PA consists in evaluation of PAC levels and ARR after withdrawal of several antihypertensive drugs that can interfere with this dosage.

Aim of the study: To evaluate the interference of drospirenone with plasma aldosterone concentration (PAC), plasma renin activity (PRA) and potassium levels in the general population. Blood sample was obtained in 25 patients taking an oral contraception (11 in drospirenone group – 14 in non drospirenone group). Comparison of PAC/PRA ratio (aldosterone to renin ratio – ARR) was also performed as this ratio is used for screening of primary aldosteronism.

Results: Age was comparable in both groups (P=0.29). PAC was significantly more elevated in patients taking drospirenone (P=0.001) while potassium levels was not significantly different (P=0.2). Interestingly, PRA levels were not different between both groups (P=0.07). In consequence, PAC/PRA was significantly increased in drospirenone group (P=0.017). Systolic pressure was significantly higher in drospirenone group while diastolic pressure was not different (P=0.02 and P=0.098 respectively). Median value of ARR in drospirenone group was 22.63.

Conclusion: Drospirenone is an effective oral contraception with antimineralocorticoid effect with the advantage of lowering water retention symptoms. In consequence of this effect, we found a significantly higher PAC and ARR levels in drospirenone group. Drospirenone should then be withdrawed before screening a patient in case of primary aldosteronism suspicion.