5α-reductase inhibitors: Evaluation of their potential confounding effect on GC-C-IRMS doping analysis.

5α-reductase inhibitors (5-ARIs) are considered by the World Anti-doping Agency as potential confounding factors in evaluating the athlete steroid profile, since they may interfere with the urinary excretion of several diagnostic compounds. We herein investigated 5α-reductase inhibitors from a different perspective, by verifying their influence on the carbon isotopic composition of 5α- and 5ß-reduced testosterone and nandrolone metabolites. The GC-C-IRMS analysis was performed on a set of urine samples collected from three male Caucasian volunteers after the acute and chronic administration of finasteride in combination with the intake of 19-norandrostenedione, a nandrolone precursor. The excretion and the isotopic profile of androsterone (A), etiocholanolone (Etio) 5α-androstane-3α,17ß-diol (5αAdiol), and 5ß-androstane-3α,17ß-diol (5ßAdiol) were determined as well as those of 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). Pregnanediol (PD) and pregnanetriol (PT) were also measured as endogenous reference compounds to define the individual endogenous isotopic profile. Our results confirmed the impact of finasteride, especially if chronically administered, on the enzymatic pathway of testosterone and nandrolone, and pointed out the influence of 5-ARIs on δ13 C values of the selected target compounds determined in the IRMS confirmation analysis.

Safety and Pharmacokinetics of Single-Dose Novel Oral Androgen 11ß-Methyl-19-Nortestosterone-17ß-Dodecylcarbonate in Men.

Context: 11ß-Methyl-19-nortestosterone-17ß-dodecylcarbonate (11ß-MNTDC) is an orally bioavailable prodrug of 11ß-methyl-19-nortestosterone (11ß-MNT) with androgenic and progestational activity. Objectives: (i) Quantify 11ß-MNT binding to androgen and progesterone receptors. (ii) Evaluate safety, tolerability, and serum gonadotropin and testosterone suppression by 11ß-MNTDC in men. Design and Setting: (i) In vitro receptor binding and transactivation studies and (ii) randomized, double-blind, placebo-controlled single-dose, dose-escalating phase I study at two academic medical centers. Participants and Intervention: Twelve healthy male volunteers were randomized (five active, one placebo) to escalating single oral doses (100, 200, 400, and 800 mg) of 11ß-MNTDC or placebo given with or without food. Main Outcome Measures: (i) In vitro 11ß-MNT/11ß-MNTDC human receptor binding and transactivation and (ii) safety and tolerability, pharmacokinetics, and quantification of serum gonadotropin and testosterone concentrations for 24 hours following dosing. Results: 11ß-MNT avidly binds and activates human androgen and progesterone receptors, but 11ß-MNTDC has minimal activity. Single oral doses of 11ß-MNTDC were well tolerated without serious adverse events. Administration of 11ß-MNTDC with food markedly increased average 11ß-MNTDC and 11ß-MNT serum concentrations (P < 0.001 for all doses) compared with fasting with a significant dose-related effect on average serum drug concentrations (P < 0.0001). The 200-, 400-, and 800-mg doses significantly suppressed average serum testosterone concentrations (P < 0.05). Conclusions: A single, oral dose of 11ß-MNTDC up to 800 mg administered with food is safe and well tolerated in healthy men. The active drug 11ß-MNT has androgenic and progestational activity, rapidly suppresses serum testosterone, and is a promising candidate for an effective once-daily oral male hormonal contraceptive.

Effects of 28 Days of Oral Dimethandrolone Undecanoate in Healthy Men: A Prototype Male Pill.

Context: Dimethandrolone (DMA) has androgenic and progestational activity. Single oral doses of DMA undecanoate (DMAU) were well tolerated and reversibly suppressed serum LH and testosterone (T) in men. Objective: Assess safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of oral DMAU. Design: Double-blind, randomized, placebo-controlled study. Setting: Two academic medical centers. Participants: Healthy men (18 to 50 years). Interventions: One hundred men received DMAU [0, 100, 200, or 400 mg, formulated in castor oil/benzyl benzoate (C) or powder (P)] for 28 days. Subjects underwent 24-hour PK sampling on days 1 and 28 and twice weekly ambulatory visits throughout treatment. Main Outcome Measures: Primary outcomes were safety and tolerability parameters (vitals, laboratory data, mood, and sexual function scores) and adverse events. Secondary outcomes were drug PK profiles and PD effects (serum LH, FSH, and sex hormones). Results: Eighty-two subjects completed the study and were included in the analysis. There were no serious adverse events. No clinically significant changes developed in safety laboratory parameters. A significant dose effect was seen for weight, hematocrit, high-density lipoprotein cholesterol, corrected QT interval, and sexual desire. Serum 24-hour average concentrations of DMAU and DMA showed dose-related increases (P < 0.001). All six subjects in the P400 group and 12 of 13 subjects in the C400 group achieved marked suppression of LH and FSH (<1.0 IU/L) and serum T (<50 ng/dL). Conclusions: Daily oral administration of DMAU for 28 days in healthy men is well tolerated. Doses of ≥200 mg markedly suppress serum T, LH, and FSH. These results support further testing of DMAU as a male contraceptive.

Comparison of the single dose pharmacokinetics, pharmacodynamics, and safety of two novel oral formulations of dimethandrolone undecanoate (DMAU): a potential oral, male contraceptive.

Dimethandrolone (DMA, 7α,11ß-dimethyl-19-nortestosterone) has both androgenic and progestational activities, ideal properties for a male hormonal contraceptive. In vivo, dimethandrolone undecanoate (DMAU) is hydrolyzed to DMA. We showed previously that single oral doses of DMAU powder in capsule taken with food are well tolerated and effective at suppressing both LH and testosterone (T), but absorption was low. We compared the pharmacokinetics and pharmacodynamics of two new formulations of DMAU, in castor oil and in self-emulsifying drug delivery systems (SEDDS), with the previously tested powder formulation. DMAU was dosed orally in healthy adult male volunteers at two academic medical centers. For each formulation tested in this double-blind, placebo-controlled study, 10 men received single, escalating, oral doses of DMAU (100, 200, and 400 mg) and two subjects received placebo. All doses were evaluated for both fasting and with a high fat meal. All three formulations were well tolerated without clinically significant changes in vital signs, blood counts, or serum chemistries. For all formulations, DMA and DMAU showed higher maximum (p < 0.007) and average concentrations (p < 0.002) at the 400 mg dose, compared with the 200 mg dose. The powder formulation resulted in a lower conversion of DMAU to DMA (p = 0.027) compared with both castor oil and SEDDS formulations. DMAU in SEDDS given fasting resulted in higher serum DMA and DMAU concentrations compared to the other two formulations. Serum LH and sex hormone concentrations were suppressed by all formulations of 200 and 400 mg DMAU when administered with food, but only the SEDDS formulation was effectively suppressed serum T when given fasting. We conclude that while all three formulations of oral DMAU are effective and well tolerated when administered with food, DMAU in oil and SEDDS increased conversion to DMA, and SEDDS may have some effectiveness when given fasting. These properties might be advantageous for the application of DMAU as a male contraceptive.

Where does hydrolysis of nandrolone decanoate occur in the human body after release from an oil depot?

Long-term therapy of nandrolone (N) is recommended to increase mineral density and muscle strength. Using a parenteral sustained release drug formulation with nandrolone decanoate (ND), therapeutic N levels can be achieved and maintained. Until now, it is unknown if hydrolysis of ND into N occurs in tissue at the injection site or after systemic absorption. Therefore, hydrolysis studies were conducted to investigate the location and rate of ND hydrolysis after its release from the oil depot. ND hydrolysis was studied in porcine tissues, to mimic the human muscular and subcutaneous tissues. Additionally, the ND hydrolysis was studied in human whole blood, plasma and serum at a concentration range of 23.3-233.3µM. ND hydrolysis only occurred in human whole blood. The hydrolysis did not start immediately, but after a lag time. The mean lag time for all studied concentrations was 34.9±2.5min. Because of a slow penetration into tissue, hydrolysis of ND is found to be very low in surrounding tissue. Therefore the local generation of the active compound is clinically irrelevant. It is argued that after injection of the oil depot, ND molecules will be transported via the lymphatic system towards lymph nodes. From here, it will enter the central circulation and within half an hour it will hydrolyse to the active N compound.

Atypical excretion profile and GC/C/IRMS findings may last for nine months after a single dose of nandrolone decanoate.

The use of the anabolic androgenic steroid nandrolone and its prohormones is prohibited in sport. A common route of nandrolone administration is intramuscular injections of a nandrolone ester. Here we have investigated the detection time of nandrolone and 19-norandrosterone and 19-noretiocholanolone metabolites in eleven healthy men after the administration of a 150 mg dose of nandrolone decanoate. The urinary concentrations of nandrolone and the metabolites were monitored by GC-MS/MS for nine months and in some samples the presence of 19-norandrosterone was confirmed by GC/C/IRMS analysis. The participants were genotyped for polymorphisms in PDE7B1 and UGT2B15 genes previously shown to influence the activation and inactivation of nandrolone decanoate. There were large inter-individual variations in the excretion rate of nandrolone and the metabolites, although not related to genetic variations in the UGT2B15 (rs1902023) and PDE7B1 (rs7774640) genes. After the administration, 19-norandrosterone was found at 2-8-fold higher concentrations than 19-noretiocholanolone. We showed that nandrolone doping can be identified 4 and 9 months after the injection of only one single dose in six and three individuals, respectively. We also noted that GC/C/IRMS confirms the presence of exogenous 19-norandrosterone in the urine samples, showing δ13 values around -32 ‰. This was true even in a sample that was not identified as an atypical finding after the GC-MS/MS analysis further showing the power of using GC/C/IRMS in routine anti-doping settings.

Fundamental understanding of drug absorption from a parenteral oil depot.

Oil depots are parenteral drug formulations meant for sustained release of lipophilic compounds. Until now, a comprehensive understanding of the mechanism of drug absorption from oil depots is lacking. The aim of this paper was to fill this gap. A clinical study with healthy volunteers was conducted. An oil depot with nandrolone decanoate and benzyl alcohol was subcutaneously administered in the upper arm of female volunteers. Pharmacokinetic profiles of both substances were related to each other and to literature data. Benzyl alcohol absorbs much more rapidly than nandrolone. In detail, it appears that benzyl alcohol enters the central compartment directly, while nandrolone decanoate is recovered in serum after a lag time. This lag time is also seen in literature data, although not reported explicitly. The absorption of nandrolone is enhanced by the presence of benzyl alcohol. This is most likely an effect of altered oil viscosity and partition coefficient between the oil and aqueous phase. The absorption rate constant of compounds is found to be related to the logP of the solubilized prodrug. The absorption rate is however not only determined by the physico-chemical properties of the formulation but also by the tissue properties. Here, it is argued that lymphatic flow must be considered as a relevant parameter.

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry method for the determination of dienogest in human plasma and its pharmacokinetic applications under fasting.

A simple, rapid and sensitive analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection with positive ion electrospray ionization was developed for the determination of dienogest in human K2 EDTA plasma using levonorgestrel d6 as an internal standard (IS). Dienogest and IS were extracted from human plasma using simple liquid-liquid extraction. Chromatographic separation was achieved on a Zorbax XDB-Phenyl column (4.6 × 75 mm, 3.5 µm) under isocratic conditions using acetonitrile-5 mm ammonium acetate (70:30, v/v) at a flow rate of 0.60 mL/min. The protonated precursor to product ion transitions monitored for dienogest and IS were at m/z 312.30 → 135.30 and 319.00 → 251.30, respectively. The method was validated with a linearity range of 1.003-200.896 ng/mL having a total analysis time for each chromatograph of 3.0 min. The method has shown tremendous reproducibility with intra- and inter-day precision (coefficient of variation) <3.97 and 6.10%, respectively, and accuracy within ±4.0% of nominal values. The validated method was applied to a pharmacokinetic study in human plasma samples generated after administration of a single oral dose of 2.0 mg dienogest tablets to healthy female volunteers and was proved to be highly reliable for the analysis of clinical samples.

Dienogest in the treatment of endometriosis.

INTRODUCTION: Dienogest (DNG) is an oral progestin, derivative of 19-nortestosterone, that has recently been introduced for the treatment of endometriosis. AREAS COVERED: This review examines the clinical efficacy, safety and tolerability of DNG in the treatment of endometriosis. The material included in the current manuscript was searched and obtained via Medline, Pubmed and EMBASE, from inception until February 2014. The term 'dienogest' was associated with the following search terms: 'endometriosis', 'pharmacokinetics', 'safety' and 'efficacy'. EXPERT OPINION: Several trials demonstrated the clinical efficacy, safety and tolerability of DNG. However the use of DNG is associated with some limitations. So far, no study investigated the potential of contraceptive effect of this treatment and therefore, it should be recommended with other methods of contraception (e.g., barrier methods). A further limitation of the use of DNG as daily therapy in the long term is that the cost of the therapy is higher than other progestins available on the market and combined oral contraceptives. Therefore, future studies should be designed to compare the efficacy and safety of DNG with other progestins.

Single, escalating dose pharmacokinetics, safety and food effects of a new oral androgen dimethandrolone undecanoate in man: a prototype oral male hormonal contraceptive.

The novel androgen, dimethandrolone (DMA) has both androgenic and progestational activities, properties that may maximize gonadotropin suppression. We assessed the pharmacokinetics of dimethandrolone undecanoate (DMAU), an orally bioavailable, longer acting ester of DMA, for male contraceptive development. Our objective was to examine the safety and pharmacokinetics of single, escalating doses of DMAU (powder in capsule formulation) administered orally with or without food in healthy men. We conducted a randomized, double-blind Phase 1 study. For each dose of DMAU (25-800 mg), 10 male volunteers received DMAU and two received placebo at two academic medical centres. DMAU was administered both fasting and after a high-fat meal (200-800 mg doses). Serial serum samples were collected over 24 h following each dose. DMAU was well tolerated without significant effects on vital signs, safety laboratory tests or electrocardiograms. When administered while fasting, serum DMA (active compound) was detectable in only 4/10 participants after the 800 mg dose. When administered with a 50% fat meal, serum DMA was detectable in all participants given 200 mg DMAU and showed a dose-incremental increase up to 800 mg, with peak levels 4-8 h after taking the dose. Serum gonadotropins and sex hormone concentrations were significantly suppressed 12 h after DMAU administration with food at doses above 200 mg. This first-in-man study demonstrated that a single, oral dose of DMAU up to 800 mg is safe. A high-fat meal markedly improved DMAU/DMA pharmacokinetics.

Pharmacokinetic-pharmacodynamic study of subcutaneous injection of depot nandrolone decanoate using dried blood spots sampling coupled with ultrapressure liquid chromatography tandem mass spectrometry assays.

CONTEXT: Testosterone (T) and nandrolone (N) esters require deep im injections by medical personnel but these often deposit injectate into sc fat so that more convenient sc self-administration may be feasible. OBJECTIVE: To investigate the feasibility and pharmacology of sc injection of N decanoate in healthy men using dried blood spot (DBS) for frequent blood sampling without clinic visits. SETTING AND DESIGN: Healthy male volunteers received 100 mg N decanoate by a single sc injection. Finger-prick capillary blood was spotted onto filter paper before injection daily at home for 21 d and stored at room temperature. Venous whole blood was also spotted onto filter paper before and weekly for 3 wk after injection. DBS were extracted for assay of N and T by liquid chromatography tandem mass spectrometry in a single batch with serum concentrations estimated with adjustment for capillary blood sample volume and hematocrit to define peak (N) or nadir (T) time and concentration from individual daily measurements. RESULTS: Daily serum N peaked 2.50 ± 0.25 (SEM) ng/mL at a median (range) of 6 (4-13) days causing a reduction in serum T from 3.50 ± 0.57 ng/mL at baseline to a nadir of 0.38 ± 0.13 (SEM) ng/mL (89 ± 3% suppression) at a median (range) of 8 (5-16) days. Simultaneously sampled capillary, venous whole blood, and serum gave almost identical results for serum T and N. Finger-pricks and sc injections were well tolerated. CONCLUSIONS: This study demonstrates that A) DBS sampling with liquid chromatography mass spectrometry steroid analysis achieves frequent time sampling in the community without requiring clinic visits, venesection, or frozen serum storage, and B) androgen esters in an oil vehicle can be delivered effectively by sc injection, thus avoiding the need for medically supervised deep-im injections.

Pharmacokinetic study of single and multiple oral administrations of 2 mg dienogest in healthy Korean women.

BACKGROUND: The progestin dienogest was developed for oral contraception, endometriosis treatment and menopause management. Dienogest's pharmacokinetics have been primarily studied in Caucasian women. This study evaluated the single- and multiple-dose pharmacokinetics of dienogest in Korean women. STUDY DESIGN: Sixteen healthy Korean adult women received a single administration of 2 mg dienogest, followed by multiple once-daily administrations for 14 days. The single-dose administration and the final dose of the multiple administrations were each followed by blood sampling over 60 h. RESULTS: The mean (SD) maximum serum concentration after multiple doses of dienogest was slightly increased compared with that after a single dose [from 51.6 (9.6) to 56.6 (11.9) ng/mL], as was the area under the concentration-time curves (AUC)0-24h [from 503 (56.3) to 613 (90.7) ng ∙ h/mL]. The linearity factor calculated by AUCs of single and multiple doses is 1.00 ± 0.14, and the terminal half-life remained unchanged when single dosing and multiple dosing were compared. CONCLUSIONS: The present study described the single- and multiple-dose pharmacokinetic profiles of dienogest in Korean women and showed linear pharmacokinetics of dienogest at steady state.

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.

Illegal treatment of barrows with nandrolone ester: effect on growth, histology and residue levels in urine and hair.

The effect of 17ß-19-nortestosterone (17ßNT) treatment of barrows on residue levels and growth was evaluated. Five barrows were treated three times during the fattening period with 17ßNT phenylpropionate (Nandrosol, nandrolone phenylpropionate 50 mg/ml,1 mg/kg body weight). Another five barrows were untreated and five boars (untreated) were kept as positive control. Boars and treated barrows showed a 13 and 9% improvement in growth compared to untreated barrows, with mean final body weights of 121.6, 117.8 and 109.0 kg, respectively. The bulbourethral glands of the treated barrows were three times heavier than untreated barrows. The histology of the prostate and bulbourethral gland of the treated barrows was comparable to the boars, whereas the control barrows showed atrophic glands. Levels of 17ßNT ester in hair from treated barrows were high, whereas boars and untreated barrows did not show levels above LLQ. It is concluded that analysis of hair can detect illegal treatment with 17ßNT ester in barrows. The size of the bulbourethral gland can also be used for screening in the slaughterhouse.

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.

Dienogest: a review of its use in the treatment of endometriosis.

Dienogest (Visanne®) is a synthetic oral progestogen with unique pharmacological properties that is indicated at a dosage of 2 mg/day for the treatment of endometriosis. It is generally highly selective for the progesterone receptor and displays strong progestational effects and moderate antigonadotrophic effects, but no androgenic, glucocorticoid or mineralocorticoid activity. Dienogest has moderate affinity for progesterone receptors (10% that of progesterone) and at a dosage of 2 mg/day only moderately suppresses estradiol levels. It has high oral bioavailability and a half-life suitable for once-daily administration. In randomized clinical trials, oral dienogest was significantly more effective than placebo in reducing pelvic pain in patients with confirmed endometriosis. In trials comparing oral dienogest for 16 or 24 weeks with gonadotropin-releasing hormone (GnRH) agonists commonly used in the treatment of endometriosis, dienogest was noninferior to depot leuprorelin in reducing pelvic pain and was not significantly different from intranasal buserelin and depot triptorelin in improving combined symptoms/signs scores or revised American Fertility Society (rAFS) staging scores, respectively. Improvements were also noted in some measures of health-related quality of life. The efficacy of dienogest was sustained during long-term treatment for more than 1 year. Dienogest was generally well tolerated and was not considered to be associated with clinically relevant androgenic effects. It appeared to have fewer hypoestrogenic effects than the GnRH agonists. Dienogest was associated with a high incidence of abnormal menstrual bleeding patterns, although this was generally well tolerated by patients, with few discontinuing therapy, and the bleeding intensity and frequency decreased over time. Therefore, oral dienogest offers an effective, generally well tolerated therapeutic option for the long-term treatment of endometriosis.

Ethinylestradiol/dienogest in oral contraception.

The low-dose combined oral contraceptive of ethinylestradiol 30 microg and dienogest 2 mg was launched in Germany in 1995, and is now the most commonly prescribed oral contraceptive in this country. Dienogest is a novel 19-nortestosterone-derived progestin with a unique pharmacokinetic and pharmacological profile, including antiandrogenic properties. Clinical studies have demonstrated that ethinylestradiol/dienogest is a reliable ovulation inhibitor with high contraceptive efficacy that is comparable with other combined oral contraceptives. It also provides effective cycle control, with reduced intensity and duration of menstrual bleeding, and improves dysmenorrhoea. The combination of ethinylestradiol and dienogest reduces serum androgen levels, and increases the levels of thyroid hormones; however, although thyroid hormone levels increase, there is no increased activity due to increases in transporter protein. Like other low-dose oral contraceptives, ethinylestradiol/dienogest has only minor influences on lipid and carbohydrate metabolism, adrenal hormones and blood pressure parameters, and appears to have a balanced effect on the haemostatic system. Ethinylestradiol/dienogest also has beneficial effects on hair and skin; a number of studies have reported decreased hair and skin greasiness, and improvements in acne vulgaris following treatment with ethinylestradiol/dienogest. After discontinuation of ethinylestradiol/dienogest, there may be a small delay in conception during the first three cycles, but there is no subsequent impairment of fertility. Furthermore, the duration of use of ethinylestradiol/dienogest does not seem to influence the rate of conception or time to conception. Ethinylestradiol/dienogest is well tolerated; adverse reactions associated with treatment include breast pain, headache and nausea/vomiting. These adverse reactions are rare and decrease in incidence over time.

Lymphatic transport of Methylnortestosterone undecanoate (MU) and the bioavailability of methylnortestosterone are highly sensitive to the mass of coadministered lipid after oral administration of MU.

The contribution of lymphatic transport to the oral bioavailability of methylnortestosterone (M) after oral administration of the lipophilic prodrug methylnortestosterone undecanoate (MU) has been evaluated, and the sensitivity of lymphatic MU transport to lymphatic lipid transport has been investigated. M and MU were administered intravenously and orally to greyhound dogs to determine absolute bioavailability after oral dosing of MU. MU was also administered orally with differing quantities of food (lipid) to lymph duct-cannulated greyhound dogs to investigate the relative roles of lymph versus blood transport on M bioavailability and the effect of lipid load on systemic exposure. The relationship between lymphatic lipid and MU transport was further investigated in anesthetized rats. The oral bioavailability of M after administration of MU was found to be highly dependent on coadministration of food, and the bioavailability of M increased approximately 700% in fed versus fasted animals. In both cases, lymph diversion resulted in negligible systemic exposure of M, indicating almost complete dependence on lymphatic transport of MU for systemic exposure of M. Lymphatic transport of MU was even more highly dependent on the quantity of coadministered lipid and increased more than 50-fold with increasing lipid load. Therefore, increasing the quantity of food or lipid coadministered with MU stimulated a significant increase in the lymphatic transport of MU and systemic exposure of M. The lipid sensitivity of lymphatic transport of MU is significantly higher than previously observed for more metabolically stable compounds, suggesting a role for coadministered lipid in promoting avoidance of enterocyte-based cleavage of MU.

Pharmacokinetics of an oral contraceptive containing oestradiol valerate and dienogest.

OBJECTIVE: To evaluate the pharmacokinetics of a combined oral contraceptive (OC) containing oestradiol valerate/dienogest (E2V/DNG) administered according to a four-phasic dosing regimen with an oestrogen step-down and a progestin step-up over 26 days of active treatment. METHODS: This Phase I, open-label study included healthy women aged 18-50 years. Treatment consisted of the administration of E2V 3 mg for 2 days, E2V 2 mg/DNG 2 mg for 5 days, E2V 2 mg/DNG 3 mg for 17 days, E2V 1 mg for 2 days, and placebo for 2 days. RESULTS: Pharmacokinetic data were analysed in 15 women. Stable E2 concentrations were maintained throughout the study. Minimum mean serum E2 levels were 33.6-64.7 pg/ml during E2V administration. The ratio of oestrone:E2 in serum was approximately 5:1. Minimum mean serum DNG levels were 6.8-15.1 ng/ml during DNG administration. Minimum concentrations of DNG increased only slightly during each phase of the regimen during which DNG was being administered. On day 24 the geometric mean C(max), C(ave) and t((1/2)) of DNG were 82.9 ng/ml, 33.7 ng/ml and 12.2 hours, respectively; the median t(max) was 1.5 hours. Serum sex hormone-binding globulin concentrations increased by 40% (within the normal range). Cortisol binding-globulin levels remained almost unchanged. Treatment was well tolerated. CONCLUSIONS: Treatment with an OC containing E2V and DNG was well tolerated and was associated with stable E2 concentrations over 28 days. The pharmacokinetics of DNG were consistent with previous findings. Minimum serum concentrations of DNG increased only slightly during phases of the regimen during which DNG was administered.

Distribution, metabolism and excretion of a synthetic androgen 7alpha-methyl-19-nortestosterone, a potential male-contraceptive.

A synthetic androgen 7alpha-Methyl-19-nortestosterone (MENT) has a potential for therapeutic use in 'androgen replacement therapy' for hypogonadal men or as a hormonal male-contraceptive in normal men. Its tissue distribution, excretion and metabolic enzyme(s) have not been reported. Therefore, the present study tested the distribution and excretion of MENT in Sprague-Dawley rats castrated 24h prior to the injection of tritium-labeled MENT ((3)H-MENT). Rats were euthanized at different time intervals after dosing, and the amount of radioactivity in various tissues/organs was measured following combustion in a Packard oxidizer. The radioactivity (% injected dose) was highest in the duodenal contents in the first 30min of injection. Specific uptake of the steroid was observed in target tissues such as ventral prostate and seminal vesicles at 6h, while in other tissues radioactivity equilibrated with blood. Liver and duodenum maintained high radioactivity throughout, as these organs were actively involved in the metabolism and excretion of most drugs. The excretion of (3)H-MENT was investigated after subcutaneous injection of (3)H-MENT into male rats housed in metabolic cages. Urine and feces were collected at different time intervals (up to 72h) following injection. Results showed that the radioactivity was excreted via feces and urine in equal amounts by 30h. Aiming to identify enzyme(s) involved in the MENT metabolism, we performed in vitro metabolism of (3)H-MENT using rat and human liver microsomes, cytosol and recombinant cytochrome P(450) (CYP) isozymes. The metabolites were separated by thin-layer chromatography (TLC). Three putative metabolites (in accordance with the report of Agarwal and Monder [Agarwal AK, Monder C. In vitro metabolism of 7alpha-methyl-19-nortestosterone by rat liver, prostate, and epididymis. Endocrinology 1988;123:2187-93]), [i] 3-hydroxylated MENT by both rat and human liver cytosol; [ii] 16alpha-hydroxylated MENT (a polar metabolite) by both rat and human hepatic microsomes; and [iii] 7alpha-methyl-19-norandrostenedione (a non-polar metabolite) by human hepatic microsomes, were obtained. By employing chemical inhibitors and specific anti-CYP antibodies, (3)H-MENT was found to be metabolized specifically by rat CYP 2C11 and 3-hydroxysteroid dehydrogenase (3-HSD) enzymes whereas in humans it was accomplished by CYP 3A4, 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and 3-HSD enzymes.