CROI 2019: advances in antiretroviral therapy.

The 2019 Conference on Retroviruses and Opportunistic Infections included many exciting advances in antiretroviral therapy (ART). Investigators presented a case report of a second patient possibly cured of HIV through an allogeneic hematopoietic stem cell transplant from a CC chemokine receptor 5-delta 32 donor. Two clinical trials of long-acting injectable cabotegravir and rilpivirine showed promising safety, efficacy, and tolerability as maintenance ART. Test-and-treat and rapid-ART-start strategies show promise in advancing progress toward the HIV care cascade 90-90-90 Joint United Nations Programme on HIV/AIDS/World Health Organization targets. However, late diagnosis and mortality after ART initiation remain high, even in the context of HIV service scale-up, and mortality from unintentional opioid overdose in people living with HIV in the United States is on the rise. In vitro studies were presented that identified and evaluated the effect of resistance-associated mutations on ART susceptibility and elucidated mechanisms of resistance. Epidemiologic data were reported on the prevalence, impact, regional variation, and changes over time of resistance-associated mutations. Decreasing regional and national rates of resistance may be a benefit of increasing use of integrase strand transfer inhibitors (InSTIs). New findings were presented on maternal and fetal health outcomes in women of reproductive potential, drug-drug interactions between hormonal contraception and ART, and further exploration of the association between InSTIs and birth defects.

No. 329-Canadian Contraception Consensus Part 4 of 4 Chapter 9: Combined Hormonal Contraception.

OBJECTIVE: To provide guidelines for health care providers on the use of contraceptive methods to prevent pregnancy and on the promotion of healthy sexuality. OUTCOMES: Overall efficacy of cited contraceptive methods, assessing reduction in pregnancy rate, safety, and side effects; the effect of cited contraceptive methods on sexual health and general well-being; and the availability of cited contraceptive methods in Canada. EVIDENCE: Medline and the Cochrane Database were searched for articles in English on subjects related to contraception, sexuality, and sexual health from January 1994 to December 2015 in order to update the Canadian Contraception Consensus published February-April 2004. Relevant Canadian government publications and position papers from appropriate health and family planning organizations were also reviewed. VALUES: The quality of the evidence is rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. Recommendations for practice are ranked according to the method described in this report. SUMMARY STATEMENTS: RECOMMENDATIONS.

The sexuological impact of hormonal contraceptives based on their route of administration.

Evidence on the effects of hormonal contraceptives on female sexuality is conflicting. We enrolled 556 women, divided into six groups: two composed of subjects using a combined hormonal contraceptive (COC) containing 0.020 ("COC20") and 0.030 ("COC30") mg of ethynyl estradiol (EE), "natural", using COC containing 1.5 mg of estradiol (E2), "ring", using a vaginal ring releasing each day 0.015 mg of EE + 0.120 of etonogestrel, "subcutaneous", using a progestin only subcutaneous contraceptive implant releasing etonogestrel and "controls", using no hormonal contraceptive methods. The subjects were required to answer to the McCoy female sexuality questionnaire and were subjected to a blood test for hormonal evaluation. An ultrasound evaluation of the dorsal clitoral artery was also performed. The higher McCoy sexological value were recorded in the subdermal group; significant differences were recorded among the groups in terms of hormone distribution, with the higher levels of androstenedione in subdermal and control groups. The ultrasound evaluation of dorsal clitoral artery shows a significative correlation between pulsatility and resistance indices and orgasm parameters of McCoy questionnaire. The recorded difference in the sexual and hormonal parameters among the studied hormonal contraceptives may guide toward the personalization of contraceptive choice.

Contraceptive safety among women with cystic fibrosis: a systematic review.

BACKGROUND: With dramatic improvements in life expectancy for cystic fibrosis (CF) patients, contraception for women with CF has become an important issue. There are theoretical concerns that hormonal contraceptive use among women with CF may impact disease severity or risk for other adverse health outcomes, including thrombosis and poor bone health, as well as concerns that malabsorption or altered drug metabolism might impact contraceptive effectiveness. OBJECTIVE: To evaluate evidence on the safety and effectiveness of contraceptive methods among women with CF. SEARCH STRATEGY: We searched the PubMed database for all articles published from database inception through October 2015. SELECTION CRITERIA: We included studies that examined measures of disease severity, other health outcomes or indicators of contraceptive effectiveness among women with CF initiating or continuing a contraceptive method. RESULTS: Seven studies met our inclusion criteria. Three observational studies of fair to poor quality suggest that use of oral contraceptives (OCs) does not negatively impact CF disease severity, defined as changes in pulmonary function, number of exacerbations or need for intravenous antibiotics. Three small studies of poor quality reported on contraceptive failure among women with CF using combined hormonal contraceptives (combined OCs, patch or ring). One pregnancy was reported in a patch user out of 43 hormonal contraceptive users across all studies. One pharmacokinetic study reported that women with CF achieve steroid hormone plasma concentrations similar to healthy women after ingestion of combined OCs. CONCLUSIONS: Limited evidence suggests that hormonal contraceptive use does not negatively impact disease severity among women with CF and that hormonal contraceptive effectiveness is not impaired by CF. Studies were limited by small sample sizes and short duration of follow-up. No studies examined the effect of hormonal contraception on thrombosis or bone health among women with CF.

Effect of mavoglurant (AFQ056), a selective mGluR5 antagonist, on the pharmacokinetics of a combined oral contraceptive containing ethinyl estradiol and levonorgestrel in healthy women.

OBJECTIVE: To compare the pharmacokinetics (PKs) of a combination oral contraceptive (OC) when given alone or concomitantly with the selective metabotropic glutamate receptor 5 antagonist mavoglurant (AFQ056). METHODS: This open-label, fixed-sequence, two-period study included 30 healthy female subjects aged 18-40 years. In period 1, a single oral dose of an OC containing 30 µg ethinyl estradiol (EE)/150 µg levonorgestrel (LNG) was administered alone. In period 2, the OC was administered with a clinically relevant multiple dose of mavoglurant 100 mg b.i.d. under steady-state conditions. Plasma concentrations of EE and LNG were measured up to 72 hours post administration, and the PK parameters Cmax and AUClast were estimated using noncompartmental methods. RESULTS: The geometric mean ratios of EE Cmax and AUClast obtained with and without mavoglurant were 0.97 (90% confidence interval (CI): 0.90-1.06) and 0.94 (90% CI: 0.86-1.03), respectively. The corresponding Cmax and AUClast for LNG were 0.81 (90% CI: 0.75-0.87) and 0.68 (90% CI: 0.63-0.73), respectively. CONCLUSIONS: In conclusion, EE PK was unchanged, whereas Cmax and AUClast of LNG were 19% and 32% lower, respectively, when given with mavoglurant Further investigation regarding the impact on contraceptive efficacy is warranted.

Obesity and hormonal contraceptive efficacy.

Obesity is a major public health concern affecting an increasing proportion of reproductive-aged women. Avoiding unintended pregnancy is of major importance, given the increased risks associated with pregnancy, but obesity may affect the efficacy of hormonal contraceptives by altering how these drugs are absorbed, distributed, metabolized or eliminated. Limited data suggest that long-acting, reversible contraceptives maintain excellent efficacy in obese women. Some studies demonstrating altered pharmacokinetic parameters and increased failure rates with combined oral contraceptives, the contraceptive patch and emergency contraceptive pills suggest decreased efficacy of these methods. It is unclear whether bariatric surgery affects hormonal contraceptive efficacy. Obese women should be offered the full range of contraceptive options, with counseling that balances the risks and benefits of each method, including the risk of unintended pregnancy.

Pharmacokinetic drug interactions involving vortioxetine (Lu AA21004), a multimodal antidepressant.

BACKGROUND AND OBJECTIVE: The identification and quantification of potential drug-drug interactions is important for avoiding or minimizing the interaction-induced adverse events associated with specific drug combinations. Clinical studies in healthy subjects were performed to evaluate potential pharmacokinetic interactions between vortioxetine (Lu AA21004) and co-administered agents, including fluconazole (cytochrome P450 [CYP] 2C9, CYP2C19 and CYP3A inhibitor), ketoconazole (CYP3A and P-glycoprotein inhibitor), rifampicin (CYP inducer), bupropion (CYP2D6 inhibitor and CYP2B6 substrate), ethinyl estradiol/levonorgestrel (CYP3A substrates) and omeprazole (CYP2C19 substrate and inhibitor). METHODS: The ratio of central values of the test treatment to the reference treatment for relevant parameters (e.g., area under the plasma concentration-time curve [AUC] and maximum plasma concentration [C max]) was used to assess pharmacokinetic interactions. RESULTS: Co-administration of vortioxetine had no effect on the AUC or C max of ethinyl estradiol/levonorgestrel or 5'-hydroxyomeprazole, or the AUC of bupropion; the 90 % confidence intervals for these ratios of central values were within 80-125 %. Steady-state AUC and C max of vortioxetine increased when co-administered with bupropion (128 and 114 %, respectively), fluconazole (46 and 15 %, respectively) and ketoconazole (30 and 26 %, respectively), and decreased by 72 and 51 %, respectively, when vortioxetine was co-administered with rifampicin. Concomitant therapy was generally well tolerated; most adverse events were mild or moderate in intensity. CONCLUSION: Dosage adjustment may be required when vortioxetine is co-administered with bupropion or rifampicin.

Effect of empagliflozin on the steady-state pharmacokinetics of ethinylestradiol and levonorgestrel in healthy female volunteers.

BACKGROUND: Empagliflozin is a potent, selective inhibitor of sodium glucose cotransporter 2 in development for the treatment of patients with type 2 diabetes mellitus. Oral contraceptives may be co-administered with antidiabetic agents over long periods of time, therefore potential drug-drug interactions between oral contraceptives and antidiabetic drugs should be investigated. OBJECTIVE: The effect of multiple oral doses of empagliflozin 25 mg once daily (qd) on the steady-state pharmacokinetics of the combined oral contraceptive ethinylestradiol (EE) 30 µg/levonorgestrel (LNG) 150 µg qd was investigated. STUDY DESIGN: This was a phase I, open-label, two-period, fixed sequence study. SETTING: The study was performed at the Human Pharmacology Centre/Department of Translational Medicine, Boehringer Ingelheim, Biberach, Germany. PARTICIPANTS: Eighteen healthy premenopausal women participated in the study. INTERVENTION: There was a mandatory run-in period in which participants received EE 30 µg/LNG 150 µg qd for 21-48 days followed by a treatment-free interval of 7 days. Participants then received EE 30 µg/LNG 150 µg qd for 14 days (reference; period 1), followed by EE 30 µg/LNG 150 µg qd plus empagliflozin 25 mg qd for 7 days (test; period 2). MAIN OUTCOME MEASURES: The pharmacokinetics of EE and LNG at steady state based on the primary endpoints of area under the steady-state plasma concentration-time curve during a dosage interval τ (AUC(τ,ss)) and maximum steady-state plasma concentration during a dosage interval (C (max,ss)) were the main outcome measures. RESULTS: The pharmacokinetics of EE and LNG were not affected by co-administration with empagliflozin. Geometric mean ratios (90 % CI) of AUC(τ,ss) and C (max,ss) for EE were 102.82 % (97.58, 108.35) and 99.22 % (93.40, 105.39), respectively. For LNG, these values were 101.94 % (98.54, 105.47) and 105.81 % (99.47, 112.55), respectively. The 90 % CIs were within the standard bioequivalence boundaries of 80-125 %. There were no relevant changes in the time to reach peak levels (t (max,ss)) or terminal elimination half-life (t (½,ss)) of EE and LNG between test and reference treatments. Ten women in each treatment had at least one adverse event (AE). Severe AEs were reported by three women in the reference period and one woman in the test period. There were no serious AEs or premature discontinuations. CONCLUSION: The combination of EE 30 µg/LNG 150 µg and empagliflozin 25 mg was well tolerated. Based on standard bioequivalence criteria, empagliflozin had no effect on the pharmacokinetics of EE and LNG, indicating that no dose adjustment of EE 30 µg/LNG 150 µg is required when empagliflozin is co-administered.

Comparison of serum and cervical mucus hormone levels during hormone-free interval of 24/4 vs. 21/7 combined oral contraceptives.

BACKGROUND: This study analyzes levels of progesterone, estradiol, norethindrone (NET) and ethinyl estradiol (EE) in serum and levels of NET in cervical mucus on the last day of the hormone-free interval (HFI) in users of 24/4 [norethindrone acetate (NETA)/EE-24] vs. 21/7 (NETA/EE-21) regimens. STUDY DESIGN: This was a randomized controlled, crossover, equivalency trial. Subjects were randomized to receive NETA/EE-24 or NETA/EE-21 for 2 months and then switched between study drugs. Blood and cervical mucus samples were obtained on Days 12-16 and on the last day of the HFI. RESULTS: From April 2010 to November 2011, 32 subjects were enrolled with 18 subjects completing all study visits. There were no statistically significant differences in either day 12-16 (p=.54) or last hormone-free day (p=.33) cervical mucus NET concentrations between the regimens. On the last day of the HFI, median serum progesterone levels did not differ significantly; however, users of NETA/EE-24 had higher levels of serum NET (p<.001) and users of NETA/EE-21 had higher levels of serum estradiol (p=.01). CONCLUSION: This data supports the fact that inhibition of the pituitary-ovarian axis occurs during oral contraceptive use and during the HFI. We demonstrated that a reduced HFI of 4 days resulted in better suppression of the ovarian hormone production, thereby reducing the risk of ovulation and potential contraceptive failure.

Enzyme induction with antiepileptic drugs: cause for concern?

Several commonly prescribed antiepileptic drugs (AEDs)-including phenobarbital, phenytoin, and carbamazepine-stimulate the synthesis of a broad range of monooxygenase and conjugating enzymes. These agents are well known to reduce the duration and action of many lipid- and non-lipid-soluble drugs, including anticoagulants, cytotoxics, analgesics, antiretrovirals, glucocorticoids, statins, antihypertensives, oral contraceptives, psychoactive drugs, immunosuppressants, and of course, other AEDs. This process, therefore, may be associated with a number of clinical problems including higher cancer mortality, progressive AIDS, transplant rejection, and unwanted pregnancy. Withdrawal of enzyme-inducing AEDs will increase the concentration of induced drugs, bringing with it substantial risk of toxicity if doses are not concomitantly reduced. Yet the potential widespread adverse health consequences of these interactions, both with AED initiation and withdrawal, remain largely underappreciated. Furthermore, induction also affects enzymes involved in endogenous metabolic pathways, and can alter bone biochemistry, gonadal steroids, and lipid markers. Therefore, enzyme-inducing AEDs may contribute to the development of a number of comorbidities, including osteoporosis, sexual dysfunction, and vascular disease. This process continues as long as the patient takes the inducer. Modern AEDs that do not possess this property have similar efficacy for the common epilepsies. Accordingly, perhaps consideration should be given to starting treatment with, or even switching patients to, non-enzyme-inducing AEDs.

Bioequivalence evaluation of a folate-supplemented oral contraceptive containing ethinylestradiol/drospirenone/levomefolate calcium versus ethinylestradiol/drospirenone and levomefolate calcium alone.

BACKGROUND: Neural tube defects (NTDs) are congenital malformations that occur during early embryonic development. Suboptimal maternal folate status is a well-known risk factor for the occurrence of NTDs, and periconceptional folic acid supplementation has been shown to reduce the risk of NTDs. Folate-supplemented oral contraceptives (OCs) offer a means of improving folate status in women of childbearing potential by increasing their likelihood of having raised folate levels at the time of conception. OBJECTIVE: This study aimed to demonstrate bioequivalence of ethinylestradiol (EE), drospirenone and L-5-methyl-tetrahydrofolate (L-5-methyl-THF; active moiety of levomefolate calcium) when taken as a new folate-supplemented OC containing EE/drospirenone/levomefolate calcium, with the respective OC containing EE/drospirenone and a tablet containing levomefolate calcium only. METHODS: This was a randomized, open-label, three-period crossover study carried out at a single centre in Germany. The study included 45 healthy women (age range 18-38 years). The women were randomly assigned to single doses of (i) EE 0.03 mg/drospirenone 3 mg/levomefolate calcium 0.451 mg (SAFYRAL®), (ii) EE 0.03 mg/drospirenone 3 mg (Yasmin®), and (iii) levomefolate calcium 0.451 mg, administered using a crossover design, with one or more menstrual cycle washout between doses. The primary variables were maximum concentrations (C(max)) and area under the concentration versus time curve (AUC) values for EE, drospirenone and L-5-methyl-THF. RESULTS: The bioavailability of EE and drospirenone was similar after administration of EE/drospirenone/levomefolate calcium and EE/drospirenone. The geometric mean ratios (GMRs) and its 90% confidence intervals (CIs) for AUC values and C(max) were within the pre-specified range (80.00-125.00%) for bioequivalence for EE and drospirenone in both formulations. The bioavailability of L-5-methyl-THF was similar after administration of EE/drospirenone/levomefolate calcium and levomefolate calcium. The respective GMRs and 90% CIs of baseline-uncorrected and -corrected AUC(last) (AUC from time zero to time of last measurable concentration) and C(max) were also within the 80.00-125.00% range. CONCLUSION: The novel folate-supplemented OC EE/drospirenone/levomefolate calcium is bioequivalent to the established OC Yasmin® (EE/drospirenone components) and to levomefolate calcium (folate component).

Evaluation of the effects of rifampicin, ketoconazole and erythromycin on the steady-state pharmacokinetics of the components of a novel oral contraceptive containing estradiol valerate and dienogest in healthy postmenopausal women.

BACKGROUND: We evaluated the effects of cytochrome P450 3A4 (CYP3A4) induction and inhibition on steady-state pharmacokinetics of the components of a novel oral contraceptive (OC) containing estradiol valerate (E2V) and dienogest (DNG). STUDY DESIGN: CYP3A4 induction was assessed in an open-label, one-arm study. Sixteen healthy postmenopausal women received E2V 2 mg/DNG 3 mg (days 1-17) and concomitant rifampicin (600 mg, days 12-16). Ratios of the area under the serum concentration-time curve between 0 and 24 h [AUC(0-24 h)] and maximum serum concentration (C(max)) of E2 and DNG on days 17 and 11 (after and before rifampicin intervention) are presented. CYP3A4 inhibition was investigated in an open-label, parallel-group study in 24 healthy postmenopausal women receiving E2V 2 mg/DNG 3 mg (days 1-14) and concomitant ketoconazole (400 mg, n=12) or erythromycin (500 mg three times daily, n=12) on days 8-14. Mean ratios of AUC(0-24 h) and C(max) of E2 and DNG on days 7 and 14 are presented. RESULTS: Concomitant administration of rifampicin decreased systemic drug exposure and yielded geometric mean ratios for E2C(max) and AUC(0-24 h) of 75% and 56%, respectively. Corresponding mean ratios for DNG were 48% and 17%, respectively. Ketoconazole coadministration increased systemic drug exposure and yielded ratios of E2 of 165% and 157%, respectively, and ratios of DNG of 194% and 286%, respectively. Erythromycin coadministration also resulted in increased mean C(max) and AUC(0-24 h) of both E2 and DNG. Geometric mean ratios of C(max) and AUC(0-24 h) for E2 were 151% and 133%, respectively. Corresponding ratios for DNG were 133% and 162%, respectively. CONCLUSIONS: Significant drug-drug interactions are apparent when CYP3A4 modulators are coadministered with the components of a novel OC containing E2V/DNG. Coadministration of CYP3A4 modulators should be avoided where possible, and another type of contraception should be used when coadministration of CYP3A4 inducers like rifampicin is unavoidable.

Estradiol valerate/dienogest: a novel combined oral contraceptive.

BACKGROUND: Estradiol valerate/dienogest (E2V/DNG) is a combined oral contraceptive (COC) with 2 new hormonal entities and a unique 4-phasic dosing regimen indicated for women to prevent pregnancy. OBJECTIVE: The purpose of this article is to review the pharmacology, pharmacokinetics, clinical efficacy, tolerability, and cost of E2V/DNG. METHODS: MEDLINE (1966-June 2011) and EMBASE (1966-June 2011) were searched for original research and review articles published in the English language using the terms Natazia or Qlaira or estradiol valerate and dienogest. The reference lists of identified articles were reviewed for additional pertinent publications. Abstracts from the 2005 to 2011 American Society of Reproductive Medicine and American College of Obstetricians and Gynecologists meetings were searched using the same terms. RESULTS: The search provided 56 articles that addressed the pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, and tolerability of E2V/DNG in women of reproductive age. Articles reporting efficacy or tolerability in the setting of menopause were excluded. The initial efficacy of E2V/DNG on ovulation inhibition was investigated in 2 prospective, randomized, open-label, Phase II dose-finding studies. The dose that was approved by the Food and Drug Administration resulted in 3.13% of women ovulating in the second cycle of treatment (90% CI, 0.2%-6.05%). Rate of pregnancy prevention with this agent was reported with a Pearl Index ranging from 0.73 to 1.27 (unadjusted) to 0.34 to 0.72 (adjusted for method failure only). The mean duration of withdrawal bleeding was 4.3 days (range, 4.0-4.6 days) among 2266 women receiving 13 treatment cycles. Adverse events reported in >1% of patients included abdominal pain, acne, breast pain, dysmenorrhea, emotional lability, headache, nausea, and weight increase. CONCLUSIONS: Estradiol valerate/dienogest is a new contraceptive formulation. It offers efficacy, tolerability, and an acceptable safety profile with a potentially better bleeding pattern than levonorgestrel-containing COCs. This COC may be especially useful for older women of reproductive age who are adherent to therapy and looking for shorter and/or lighter menstrual cycles. Studies will need to be performed to determine whether clinically significant differences in outcomes exist among E2V/DNG and other available COCs.

Carbamazepine coadministration with an oral contraceptive: effects on steroid pharmacokinetics, ovulation, and bleeding.

PURPOSE: Antiepileptic drugs (AEDs) are widely used in reproductive-age women. The AED carbamazepine (CBZ) induces the hepatic cytochrome P450 system, thereby accelerating hormone metabolism. We sought to assess the pharmacodynamic effects of CBZ on breakthrough bleeding and ovulation during oral contraceptive (OC) use. METHODS: A double-blind, randomized, crossover study of healthy women ages 18-35 years. Participants took an OC containing 20 µg ethinyl estradiol (EE) and 100 µg levonorgestrel (LNG) for 4 months. Concurrently, participants took 600 mg CBZ or a matching placebo for 2 months each, administered in random order. During the second month of CBZ or placebo, we measured EE and LNG levels 12 times over 24 h, ovarian follicular diameters with eight biweekly vaginal ultrasounds, weekly progesterone levels, and bleeding (using a diary). KEY FINDINGS: We enrolled 25 women; 10 completed the study. Five women discontinued because of reversible CBZ side effects. Mean area under the curve (AUC) measurements were lower during CBZ use compared to placebo for EE (1,778 vs. 986 pg*h/ml, p < 0.001) and LNG (24.8 vs. 13.8 pg*h/ml, p = 0.04). Ovulation occurred in 5 of 10 CBZ cycles compared to 1 of 10 placebo cycles (p = 0.06). Three or more days of breakthrough bleeding occurred during 8 of the 10 CBZ cycles compared to 2 of the 10 placebo cycles (p = 0.07). SIGNIFICANCE: A commonly used dose of CBZ decreased levels of contraceptive steroids, increased breakthrough bleeding, and permitted ovulation during use of a low-dose OC. Women treated with CBZ are not adequately protected from pregnancy by low-dose OCs.

Nomegestrol acetate: pharmacology, safety profile and therapeutic efficacy.

This review summarizes the pharmacology, safety and clinical efficacy of nomegestrol acetate, based on the available published literature, and assesses the pharmacological characteristics that underlie a role in different gynaecological disorders and hormone replacement therapy (HRT), and a potential role in combination estrogen/progestogen oral contraception. Nomegestrol acetate is a potent, orally active progestogen with a favourable tolerability profile and neutral metabolic characteristics. Unlike the majority of older progestogens, which were 19-nortestosterone derivatives synthesized primarily for their antigonadotropic activity as a component of hormonal contraception in combination with an estrogen, nomegestrol acetate is a 19-norprogesterone derivative designed to bind specifically to the progesterone receptor, and is relatively lacking in affinity for other steroid receptors. Nomegestrol acetate exerts strong antiestrogenic effects at the level of the endometrium and has potent antigonadotropic activity, but without any residual androgenic or glucocorticoid properties. At a dosage of 1.25 mg/day, nomegestrol acetate inhibits ovulation while permitting follicle growth, whereas at dosages of 2.5 or 5 mg/day, both ovulation and follicle development are suppressed. The antigonadotropic action of nomegestrol acetate is mediated, like other progestins, at the hypothalamic and pituitary level. Moreover, nomegestrol acetate has partial antiandrogenic activity. Absorption of nomegestrol acetate is rapid after oral administration, reaching a peak serum concentration within 4 hours, with a terminal half-life of approximately 50 hours. Nomegestrol acetate has been used successfully for the treatment of some gynaecological disorders (menstrual disturbances, dysmenorrhoea, premenstrual syndrome) and as a component of HRT in combination with estradiol for the relief of menopausal symptoms; it has been approved in Europe as monotherapy for the treatment of the menopausal syndrome, uterine diseases and menorrhagia, and in combination with an estrogen for the treatment of menopausal symptoms. In vitro data suggest that nomegestrol acetate preserves the beneficial haemostatic effects of estrogen; furthermore, nomegestrol acetate has a neutral or beneficial effect on lipid profiles, and does not adversely affect glucose metabolism or bodyweight. Nomegestrol acetate has shown a lack of profilerative activity in normal and cancerous breast tissue, and does not have a deleterious effect on bone remodelling. These potent antigonadotropic properties, and other beneficial metabolic and pharmacological characteristics, suggest that nomegestrol acetate can be an effective progestogen for use in combination with an estrogen in oral estrogen/progestogen contraceptive treatment and in HRT, while it also provides some non-contraceptive benefits for women's health.

In vivo absorption of steroidal hormones from smart polymer based delivery systems.

The purpose of this study was to develop smart polymer based controlled delivery systems to deliver steroidal hormones after single subcutaneous (s.c.) injection at predetermined rates over extended period of time. In vivo absorption and pharmacokinetics of levonorgestrel (LNG) and testosterone (TSN) were investigated from the thermosensitive and phase sensitive polymeric controlled delivery systems. A selective, reliable, and rapid method for determination of serum LNG concentration was developed using high-performance liquid chromatography-tandom mass spectrometry with atmospheric pressure chemical ionization interface (HPLC-MS-MS with APCI), while TSN in serum samples was detected and quantified by a competitive immunoassay. The delivery systems controlled the absorption of LNG in rabbits up to 6 weeks from thermosensitive and approximately 4 weeks from phase sensitive polymeric delivery systems. In vivo study of TSN delivery systems in castrated rabbits controlled the release of TSN for at least 2 months from both thermosensitive and phase sensitive polymers. Thermosensitive and phase sensitive polymer formulations significantly (p < 0.05) increased relative bioavailability of steroidal hormones compared to control. In conclusion, thermosensitive and phase sensitive polymer based delivery systems controlled the release in vivo in rabbits for longer duration after single s.c. injection.

Oral contraceptives.

Nearly 50 years ago, the introduction of Enovid (norethynodrel 10 microg and mestranol 150 microg), which provided convenient and reliable contraception, revolutionized birth control. Reports of interactions between oral contraceptives (OCs) and other drugs began to trickle into the literature. At first, these drug interactions appeared to be random and unrelated. Increased understanding of P450 enzymes and phase II reactions of sulfation and glucuronidation has permitted preliminary categorization and assessment of the clinical relevance of these drug interactions.