The weight of current evidence seems to indicate that combination oral contraceptives probably do not affect the composition of milk substantially in healthy, well-nourished mothers and do not adversely affect long-term infant growth and development. Combined oral contraceptives might transiently affect growth negatively during the first month after introduction. The magnitude of the effect on lactation likely depends on the dose and the time of introduction postpartum. A treatment scheme has been reported for mothers with hypergalactia that uses low-dose, combined oral contraceptives to decrease milk supply.[1] Ethinyl estradiol in doses greater than 30 mcg daily can suppress lactation and lead to more supplementation and possibly earlier discontinuation of breastfeeding than nonhormonal or progestin-only contraception. Additionally, introduction of an estrogen before 3 weeks postpartum may increase the risk of thromboembolism in postpartum women. Rare cases of reversible breast enlargement in breastfed infants have been reported, mostly with estrogen doses higher than are currently used. Based on the available evidence, expert opinion in the United States states that postpartum women who are breastfeeding should not use combined hormonal contraceptives during the first 3 weeks after delivery because of concerns about increased risk for venous thromboembolism and generally should not use combined hormonal contraceptives during the fourth week postpartum because of concerns about potential effects on breastfeeding performance. Postpartum breastfeeding women with other risk factors for venous thromboembolism generally should not use combined hormonal contraceptives 4 to 6 weeks after delivery.[2] World Health Organization guidelines are more restrictive, stating that combined oral contraceptives should not be used in nursing mothers before 42 days postpartum and the disadvantages of using the method generally outweigh the advantages between 6 weeks and 6 months postpartum.[3]

LCZ696 is a novel angiotensin receptor neprilysin inhibitor in development for the treatment of cardiovascular diseases. Here, we assessed the potential for pharmacokinetic drug-drug interaction of LCZ696 (400 mg, single dose or once daily [q.d.]) when co-administered with omeprazole 40 mg q.d. (n = 28) or metformin 1000 mg q.d. (n = 27) or levonorgestrel-ethinyl estradiol 150/30 μg single dose (n = 24) in three separate open-label, single-sequence studies in healthy subjects. Pharmacokinetic parameters of LCZ696 analytes (sacubitril, LBQ657, and valsartan), metformin, and levonorgestrel-ethinyl estradiol were assessed. Omeprazole did not alter the AUCinf of sacubitril and pharmacokinetics of LBQ657; however, 7% decrease in the Cmax of sacubitril, and 11% and 13% decreases in AUCinf and Cmax of valsartan were observed. Co-administration of LCZ696 with metformin had no significant effect on the pharmacokinetics of LBQ657 and valsartan; however, AUCtau,ss and Cmax,ss of metformin were decreased by 23%. Co-administration of LCZ696 with levonorgestrel-ethinyl estradiol had no effect on the pharmacokinetics of ethinyl estradiol and LBQ657 or AUCinf of levonorgestrel. The Cmax of levonorgestrel decreased by 15%, and AUCtau,ss and Cmax,ss of valsartan decreased by 14% and 16%, respectively. Co-administration of LCZ696 with omeprazole, metformin, or levonorgestrel-ethinyl estradiol was not associated with any clinically relevant pharmacokinetic drug interactions.

A 91-day extended-cycle oral contraceptive (OC) consisting of levonorgestrel/ethinylestradiol 150/30 µg for 84 days and ethinylestradiol 10 µg for 7 days (Seasonique(®)) has recently been approved for the prevention of pregnancy in adult women in the EU. This regimen allows for a reduction in the number of withdrawal bleeding episodes to four per year, compared with 13 episodes per year with conventional 28-day regimens. Seasonique(®) was effective in preventing pregnancy in a large (n = 1006), noncomparative trial of healthy, sexually active women. In this trial, the overall Pearl index (pregnancies per 100 woman-years of use) in women aged 18-35 years (n = 621) was 0.76 and the Pearl index for method-failure (compliant use) was 0.26. Scheduled (withdrawal) bleeding and/or spotting remained fairly constant over time, with a mean of 2 days of bleeding and 1 day of spotting per each 91-day cycle. Unscheduled bleeding and unscheduled spotting was highest during the first few cycles of use and decreased thereafter. Seasonique(®) was generally well tolerated, with a tolerability profile in line with that expected for OCs. Seasonique(®) extends the contraceptive options currently available to women, particularly in those who desire fewer withdrawal bleeding episodes.

Brivaracetam is a high-affinity synaptic vesicle protein 2A ligand, in Phase III clinical development for epilepsy. This study assessed the effect of brivaracetam 400 mg/day on the pharmacokinetics and pharmacodynamics of a combination oral contraceptive (OC) containing 30 µg ethinylestradiol and 150 µg levonorgestrel, in healthy pre-menopausal women. This open-label, single-center, randomized, two-way crossover, multiple oral dose study (N01080) included two consecutive 28-day cycles without (control) or with brivaracetam (test), and a 28-day follow-up. OC was taken on Days 1–21 of every cycle and brivaracetam 200 mg twice daily was administered on Days 1–20 of the test cycle. Ethinylestradiol and levonorgestrel pharmacokinetics were determined on Day 20 and endogenous hormones were measured frequently during both control and test cycles. Overall, 23/24 participants (age: 19–39 years) completed the study. AUC ratio (90% confidence interval) for brivaracetam versus control was 0.73 (0.69, 0.78) for ethinylestradiol and 0.78 (0.72, 0.83) for levonorgestrel, outside pre-defined bioequivalence limits (0.80–1.25). Levels of endogenous hormones were similar and normal during brivaracetam and control cycles. Brivaracetam in combination with OC was well tolerated. Brivaracetam 400 mg/day co-administered with a combination OC in healthy women reduced ethinylestradiol and levonorgestrel plasma levels but did not result in ovulation.