Prothrombotic effects and clinical implications of third-generation oral contraceptives use

Hemorheological mechanisms for increased thrombosis in subjects using gestodene

There are several possible mechanisms by which combined oral contraceptives (COC) use increase venous thromboembolism (VTE) risk. Melodene® is a monophasic COC containing the third-generation progestin Gestodene (GSD), which is associated with increased risk of VTE. Therefore, the aim of this study was to investigate the possible alterations in viscoelastic parameters of whole blood and plasma clots along with the biophysical characteristics of erythrocytes and specifically fibrin fibers in females using a COC containing GSD. GSD appeared to have a significant impact on the biophysical characteristics of fibrin fiber networks. When GSD is combined with ethinylestradiol the viscoelastic properties of whole blood clots tend to become more prothrombotic. The alterations to and aggregation of erythrocytes accompanied with spontaneous formation of a fibrin "blanket" provides a possible mechanism for the increased occurrence of "red" clots, which can lead to occlusions in the vascular system. Thus, the increased risk of VTE associated with these COCs can be attributed to these erythrocyte-and-fibrin-rich-clots occluding venous vessels. However, our findings also propose that these changes to the biophysical properties of both erythrocytes and fibrin, specifically spontaneous expansion of deformed fibrin networks, can also occlude vessels in the microcirculation, which could have lasting, subclinical complications for female users. We recommend that a thorough risk assessment, with specific focus on coagulation and other factors affecting fibrin formation, be done for each female before prescribing a GSD-containing COC. Females that "qualify" then need to be monitored on a regular basis to lower the risk of thrombotic events. RESEARCH HIGHLIGHTS: Gestodene in combination with ethinyl estradiol significantly impacts the biophysical characteristics of erythrocytes and fibrin fiber networks. These changes, specifically spontaneous expansion of deformed fibrin networks, can occlude vessels in the microcirculation, which could have lasting, subclinical complications for the female user. The changes observed for specifically erythrocytes and fibrin show that the hormone formulation investigated contribute to a thrombogenic profile for female users.

Comparison of the impact of four generations of progestins on hemostatic variables

This study was undertaken to evaluate the impact of progestins as part of low-estrogen (ethinyl estradiol [EE2] ≤35 μg) combined oral contraceptives (COCs) on hemostatic variables. One hundred ninety-five healthy women took oral contraceptives with following formulations: 35 EE2/norgestimate (NGM), 35 EE2/cyproterone acetate, 35 EE2/norethisterone, 30 EE2/levonorgestrel, 30 EE2/drospirenone (DRSP), 20 EE2/gestodene, and 20 EE2/DRSP, for 6 months. Hemostatic assays (prothrombin time, activated partial thromboplastin time, fibrinogen, resistance to activated protein C ratio, protein C, protein S, factor VIII [FVIII], antithrombin, plasminogen, α2-antiplasmin, inhibitor of plasminogen activator type 1 [PAI-1] and d-dimers) were performed in 3 time points: at baseline, after 3, and 6 cycles. For each formulation, results were compared according to baseline values, intergroup analysis, and the amount of estrogen or progestin component. Most of the variables were changed except FVIII. Significant difference between oral contraceptives was found in antithrombin, protein C, protein S activities, and PAI-1 values, but changes were mostly within reference range.

Factor V Leiden, prothrombin G20210A substitution and hormone therapy: indications for molecular screening

Venous thromboembolism is a well-known complication of oral contraception and hormonal replacement therapy. Inherited thrombophilia is viewed as an important determinant in modulating the effects of estrogens on thrombotic risk. An increasing number of kits for thrombophilic mutations [factor V Leiden, G20210A prothrombin and methylenetetrahydrofolate reductase (MTHFR) C677T genes] are becoming commercially available, and screening for inherited thrombotic risk is among the most requested genetic tests in molecular diagnostic laboratories. However, the question of routine genetic screening for thrombophilia before prescribing hormones is still a matter of debate. The purpose of this article is to discuss the usefulness and practical applications of thrombotic genetic testing to identify which women should be tested to improve both the safety and efficacy of individualized estrogen therapy.

A Review of Transdermal Hormonal Contraception

Imperfect use of contraceptive methods notably increases the likelihood of pregnancy. One means of improving user adherence with hormonal contraception is to minimize the dosing schedule. Two forms of hormonal contraceptive have currently achieved this goal: the transdermal patch and the vaginal ring. The first and only transdermal contraceptive patch to receive worldwide regulatory approval (ethinylestradiol/norelgestromin) is a convenient approach to contraception that has a similar efficacy to oral contraceptives (OCs), but with the benefit of once-weekly administration. In addition, transdermal delivery of contraceptive hormones eliminates variability in gastrointestinal absorption, avoids hepatic first-pass metabolism, and prevents the peaks and troughs in serum concentrations that are seen with OCs. Norelgestromin, the progestin contained in the patch, is the active metabolite of norgestimate and is structurally related to 19-nortestosterone. Norgestimate and norelgestromin mimic the physiologic effects of progesterone at the progesterone receptor; however, norelgestromin has negligible direct or indirect androgenic activity, suggesting that it may be suitable for women with disorders related to androgen excess (such as hirsutism, acne, and lipid disorders).Contraceptive effectiveness is usually a function of the efficacy of a contraceptive in combination with compliance with its dosing regimen. The efficacy of the contraceptive patch has been clearly demonstrated in three phase III trials, two of which were randomized comparisons with an OC. The likelihood of pregnancy was similar between these contraceptive methods; however, compliance with the patch was notably better, particularly in younger women. The safety and tolerability profile of the patch was similar to that of the OC. A cost-effectiveness analysis has suggested that the contraceptive patch is more cost effective than the OC, due to decreased costs related to unwanted pregnancy.