The pharmacokinetics and pharmacodynamics of dehydroepiandrosterone during use of an ethinylestradiol- and drospirenone-containing oral contraceptive.

BACKGROUND: Combined oral contraceptives (COCs) reduce the levels of ovarian and adrenal androgens. Co-administration of dehydroepiandrosterone (DHEA) may normalise androgen levels during COC use. OBJECTIVE: To investigate the effect of the addition of DHEA to a COC on the pharmacokinetics (PK) and pharmacodynamics (PD) of DHEA and its sulphate (DHEA-S), and on levels of total and free testosterone (T). METHODS: In a prospective, randomised, double-blind, placebo-controlled, cross-over study involving 21 female volunteers, the PK and PD of DHEA and DHEA-S were investigated during the use of one cycle of a COC containing 30 µg ethinylestradiol (EE) and 3 mg drospirenone (DRSP) with and without daily co-administration of 50 mg DHEA. RESULTS: Treatment during one cycle with a COC containing EE and DRSP reduces the exposure to DHEA and DHEA-S by at least 20%. This loss of adrenal androgens can be fully compensated by daily oral co-administration of 50 mg DHEA. With DHEA co-administration total T levels rise significantly (1.44 nmol/L with DHEA vs. 0.82 nmol/L with placebo; p < 0.001). Free T levels decrease significantly with both DHEA and placebo treatment, but significantly less during co-administration of DHEA (6.34 pmol/L with DHEA vs. 3.96 pmol/L with placebo; p < 0.001). CONCLUSION: By adding DHEA to a COC the loss of adrenal and ovarian androgens can be restored.

The bioequivalence of the contraceptive steroids ethinylestradiol and drospirenone is not affected by co-administration of dehydroepiandrosterone.

OBJECTIVES: To study the effect of co-administration of 50 mg dehydroepiandrosterone (DHEA) on the bioequivalence of ethinylestradiol (EE) and drospirenone (DRSP) in women who were using a combined oral contraceptive (COC) containing 30 µg EE and 3 mg DRSP, and to estimate whether the addition of DHEA to this COC affects the serum levels and the bioequivalence of the synthetic contraceptive steroids. METHODS: This was a randomised, double-blind, two-period crossover study. Participants received two EE/DRSP COC treatment cycles in random order, one with and one without daily 50 mg DHEA , separated by a 28-day wash-out cycle during which the subjects used an EE/levonorgestrel (LNG) COC without DHEA. Serum levels of EE and DRSP were measured according to a sampling scheme allowing pharmacokinetic evaluations. RESULTS: Addition of DHEA to an EE/DRSP COC had no effect on serum levels of EE and DRSP. The COC regimens with and without DHEA were bioequivalent. Oestradiol levels were equally suppressed during pill intake, whether with placebo or DHEA. CONCLUSION: Adding DHEA to a COC containing EE and DRSP does not affect the pharmacokinetic properties of EE and DRSP. Therefore, it will most likely not affect its contraceptive efficacy.

Vasorelaxing effects of estetrol in rat arteries.

This study compared ex vivo relaxing responses to the naturally occurring human hormone estetrol (E(4)) vs 17ß-estradiol (E(2)) in eight different vascular beds. Arteries were mounted in a myograph, contracted with either phenylephrine or serotonin, and cumulative concentration-response curves (CRCs) to E(4) and E(2) (0·1-100  µmol/l) were constructed. In all arteries tested, E(4) had lower potency than E(2), although the differential effect was less in larger than smaller arteries. In uterine arteries, the nonselective estrogen receptor (ER) blocker ICI 182 780 (1  µmol/l) caused a significant rightward shift in the CRC to both E(4) and E(2), indicating that the relaxation responses were ER dependent. Pharmacological blockade of nitric oxide (NO) synthases by N(ω)-nitro-L-arginine methyl ester (L-NAME) blunted E(2)-mediated but not E(4)-mediated relaxing responses, while inhibition of prostaglandins and endothelium-dependent hyperpolarization did not alter relaxation to either E(4) or E(2) in uterine arteries. Combined blockade of NO release and action with L-NAME and the soluble guanylate cyclase (sGC) inhibitor ODQ resulted in greater inhibition of the relaxation response to E(4) compared with E(2) in uterine arteries. Endothelium denudation inhibited responses to both E(4) and E(2), while E(4) and E(2) concentration-dependently blocked smooth muscle cell Ca(2)(+) entry in K(+)-depolarized and Ca(2)(+)-depleted uterine arteries. In conclusion, E(4) relaxes precontracted rat arteries in an artery-specific fashion. In uterine arteries, E(4)-induced relaxations are partially mediated via an endothelium-dependent mechanism involving ERs, sGC, and inhibition of smooth muscle cell Ca(2)(+) entry, but not NO synthases or endothelium-dependent hyperpolarization.