Simultaneous quantitation of multiple contraceptive hormones in human serum by LC-MS/MS

OBJECTIVE

The objective was to develop a method to simultaneously quantify five commonly used hormonal contraceptives (HCs) and two endogenous sex steroids by liquid chromatography-tandem triple quadrupole mass spectrometry (LC-MS/MS) and apply this method to human serum samples.

STUDY DESIGN

We developed a method to simultaneously analyze ethinyl estradiol (EE2), etonogestrel (ENG), levonorgestrel (LNG), medroxyprogesterone acetate (MPA) and norethisterone (NET), along with estradiol (E2) and progesterone (P4), in human serum for a Shimadzu Nexera-LCMS-8050 LC-MS/MS platform. We analyzed serum collected from women self-reporting use of oral contraceptives, contraceptive implants or injectable contraceptives (n=14) and normally cycling women using no HC (n=15) as well as pooled samples from women administered various HCs (ENG, n=6; LNG, n=14; MPA, n=7; NET, n=5).

RESULTS

Limits of quantitation were 0.010ng/mL for E2, EE2 and P4; 0.020ng/mL for ENG, LNG and MPA; and 0.040ng/mL for NET. Precisions for all assays, as indicated by coefficient of variation, were less than or equal to 12.1%. Accuracies for all assays were in the range of 95%-108%. Endogenous hormone values obtained from analysis of human serum samples are in agreement with levels previously reported in the literature for normally cycling women as well as for women taking the appropriate HC.

CONCLUSIONS

We have developed a robust, accurate and sensitive method for simultaneously analyzing commonly used contraceptive steroids and endogenous sex steroids in human serum.

IMPLICATIONS

This analytical method can be used for quantitating contraceptive steroid levels in women for monitoring systemic exposure to determine drug interactions, nonadherence, misreporting and proper dosing.

Three-step method for menstrual and oral contraceptive cycle verification

OBJECTIVES

Fluctuating endogenous and exogenous ovarian hormones may influence exercise parameters; yet control and verification of ovarian hormone status is rarely reported and limits current exercise science and sports medicine research. The purpose of this study was to determine the effectiveness of an individualised three-step method in identifying the mid-luteal or high hormone phase in endogenous and exogenous hormone cycles in recreationally-active women and determine hormone and demographic characteristics associated with unsuccessful classification.

DESIGN

Cross-sectional study design.

METHODS

Fifty-four recreationally-active women who were either long-term oral contraceptive users (n=28) or experiencing regular natural menstrual cycles (n=26) completed step-wise menstrual mapping, urinary ovulation prediction testing and venous blood sampling for serum/plasma hormone analysis on two days, 6-12days after positive ovulation prediction to verify ovarian hormone concentrations.

RESULTS

Mid-luteal phase was successfully verified in 100% of oral contraceptive users, and 70% of naturally-menstruating women. Thirty percent of participants were classified as luteal phase deficient; when excluded, the success of the method was 89%. Lower age, body fat and longer menstrual cycles were significantly associated with luteal phase deficiency.

CONCLUSIONS

A step-wise method including menstrual cycle mapping, urinary ovulation prediction and serum/plasma hormone measurement was effective at verifying ovarian hormone status. Additional consideration of age, body fat and cycle length enhanced identification of luteal phase deficiency in physically-active women. These findings enable the development of stricter exclusion criteria for female participants in research studies and minimise the influence of ovarian hormone variations within sports and exercise science and medicine research.

Weight, pregnancy and oral contraceptives affect intravenous paracetamol clearance in young women

OBJECTIVES

Because of the extensive variability in paracetamol clearance in young women, published data were pooled with newly collected observations in search of covariates of paracetamol pharmacokinetics (PK) within this specific population.

SUBJECTS AND METHODS

PK estimates and clinical characteristics [pregnant, weight, exposure to oral contraceptives (OC)] in young women following IV loading dose (2 g paracetamol) were pooled, using a non-compartmental linear disposition model in individual time-concentration profiles. Data were reported by median and range. Rank correlation was used to link clearance (l/h) to weight, Mann Whitney U test to compare clearance (l/h.m-2) between subgroups (pregnant, OC exposure). Finally, a multiple regression model with clearance (l/h) in all women and all non-pregnant women was performed.

RESULTS

Based on 73 paracetamol PK estimates, a 8-fold variability in clearance (range 7.1-62.2 l/h) was documented, in part explained by a correlation (r2=0.36) between clearance (l/h) and weight. Clearance (l/h and l/h.m-2) and distribution volume (l) at delivery (n=36) were higher compared to non-pregnant observations. In non-pregnant women, women on OC (n=20) had a higher paracetamol clearance (l/h.m-2) compared to women (n=17) not on OC (p = 0.023). Weight (p = 0.0043) and pregnancy (p = 0.02) were independent variables (r=0.56) of paracetamol clearance (l/h). In non-pregnant women, weight (p = 0.009) and OC exposure (p = 0.03) were independent variables (r=0.51).

CONCLUSIONS

Weight, pregnancy and OC result in higher clearance of IV paracetamol in young women. Besides compound specific relevance, these findings also unveil covariates of drug metabolism in young women.

Tissue-specific bioconcentration of the synthetic steroid hormone medroxyprogesterone acetate in the common carp (Cyprinus carpio)

The steroid hormone medroxyprogesterone acetate (MPA), commonly used in oral and injectable contraceptives, has been detected in surface and wastewaters near urban and agricultural areas in several rivers of the world. The objectives of this study were to examine the accumulative potential and tissue distribution of MPA in fish. A freshwater species, the common carp (Cyprinus carpio), was exposed to 100 μg/L of MPA for a 7-day period followed by a depuration phase in which fish were maintained in dechlorinated tap water for an additional 7 days. Tissues (muscle, brain, plasma, and liver) were sampled during the uptake (days 1, 3, and 7) and depuration (day 14) phases of the experiment. Tissue-specific bioconcentration factors (BCF) ranged from 4.3 to 37.8 and uptake was greatest in the liver>brain>plasma and lowest in the muscle. From a regulatory standpoint, MPA shows little tendency to bioaccumulate in fish.

Delay of Ovulation by Meloxicam in Healthy Cycling Volunteers: A Placebo-Controlled, Double-blind, Crossover Study

This study aimed to assess the effect of meloxicam on female ovulation. Twenty consented fertile females were monitored for 4 menstrual cycles: a baseline cycle, 2 treatment cycles, and a washout cycle between treatment cycles. In the first cycle visit, transvaginal ultrasound was performed, a blood sample for progesterone and meloxicam analysis was withdrawn, and volunteers were given a luteinizing hormone (LH) urine test kit and meloxicam or placebo. Volunteers started the treatment on the following day and asked to return the day the LH kit was positive to detect the dominant follicle. At subsequent visits, transvaginal ultrasound and progesterone and meloxicam levels were investigated. Compared to placebo, a 5-day delay in follicle rupture, a 55.7% increase in the mean maximum follicle diameter, and 33.5% decrease of plasma progesterone level were observed in the meloxicam-treated group. Such demonstrated meloxicam effects were reversed in participants who were randomized to meloxicam first and then placebo. Only minor side effects were reported by volunteers during the course of treatment. It is concluded that meloxicam resulted in a reversible delay of ovulation, an increase in follicular diameter, and a decrease in plasma progesterone level.

Pharmacokinetic interaction of solifenacin with an oral contraceptive containing ethinyl estradiol and levonorgestrel in healthy women: a double-blind, placebo-controlled study

BACKGROUND

Solifenacin succinate (YM905; Vesicare, Astellas Pharma Inc., Tokyo, Japan) is a new once-daily, orally administered muscarinic receptor antagonist under investigation for the treatment of overactive bladder.

OBJECTIVE

The aim of this study was to evaluate the effect of solifenacin on the pharmacokinetic (PK) parameters of an oral contraceptive (OC) containing ethinyl estradiol (EE) and levonorgestrel (LNG).

METHODS

In a double-blind, placebo-controlled, 2-period, crossover study, 24 healthy, young, white women received a combined OC (EE 30 microg + LNG 150 microg) daily for two 21-day cycles, separated by a 7-day washout. On day 12 of each cycle, subjects began a 10-day regimen of solifenacin 10 mg QD, which is 2 times the suggested starting dose, or placebo. Subjects crossed over to the other treatment arm for the second cycle. Primary PK end points were C(max) and AUC from time 0 to 24 hours (AUC(0-24 h)) for EE and LNG. Women ranged in age from 20 to 37 years and had a mean body weight of 64 kg, mean height of 167.4 cm, and mean body mass index of 23 kg/m2. Seven women had never smoked, while 5 were former smokers and 12 were regular smokers. Safety assessments included the nature, frequency, and severity of spontaneously reported or observed adverse events, vital signs, electrocardiogram, laboratory values, and physical examination.

RESULTS

Statistical analysis of AUC(0-24 h)/product of baseline concentration and total blood sampling time, and C(max)/baseline concentration ratios of solifenacin versus placebo for EE and LNG found the 90% CI to be within the predefined range of 0.8 to 1.25 (EE: 0.854-1.164 and 0.822-1.167; LNG: 0.920-1.125 and 0.910-1.139). The number of samples with non-quantifiable luteinizing hormone (LH) and folliclestimulating hormone (FSH) levels were comparable after administration of the OC with either solifenacin or placebo. The adverse event most frequently reported was dry mouth (solifenacin, n = 25 [9 mild, 13 moderate, and 3 severe] vs placebo, n = 1 [moderate]). There were no clinically relevant effects on vital signs, electrocardiogram, or laboratory parameters.

CONCLUSIONS

A PK interaction between solifenacin and the OC containing EE and LNG was not found in this study. Solifenacin was not found to have altered suppression of LH or FSH. The drug was well tolerated in these healthy, young, white, adult female volunteers.

Pharmacokinetics and safety of tanaproget, a nonsteroidal progesterone receptor agonist, in healthy women

OBJECTIVE

This study aimed to evaluate the pharmacokinetics, pharmacodynamics and safety of the nonsteroidal progesterone receptor agonist, tanaproget.

METHODS

A randomized, double-blind, placebo-controlled, sequential-group study of ascending single doses of tanaproget was conducted in healthy, 25- to 45-year-old women on cycle days 8 to 12. Eight subjects (six active, two placebo) per cohort received a dose of 0.1, 0.3, 1, 3, 7 (+/-high-fat meal) or 15 mg.

RESULTS

The maximum concentration (C(max)) of tanaproget occurred approximately 2 to 3 h after administration. The elimination half-life (t(1/2)) ranged from 12 to 30 h, and the oral clearance was approximately 70 L/h. The pharmacokinetics of tanaproget was not noticeably altered with a high-fat meal. All doses of tanaproget decreased cervical mucus scores (using a modified Insler method), indicating poor production and poor quality of cervical mucus. The most frequent treatment-emergent adverse events were vaginal bleeding/spotting, abdominal cramping and vomiting; their incidence was not dose related and most events were mild.

CONCLUSIONS

Tanaproget was safe and well tolerated, decreased cervical mucus scores and had a pharmacokinetic profile acceptable for use as a once-daily oral contraceptive.

Pharmacokinetic interaction of tetracycline with centchroman in healthy female volunteers

OBJECTIVES

We aimed to investigate the effect of tetracycline coadministration, with and without lactic acid bacillus spores supplementation, on the pharmacokinetics of centchroman, a nonsteroidal oral contraceptive, in healthy female volunteers.

PARTICIPANTS AND METHODS

The study was a single-centre, single-blinded, randomised, parallel treatment study in healthy female subjects of reproductive age randomised to two groups (11 subjects in each group). On day 1, subjects were given either a single oral dose of centchroman 30 mg with tetracycline 250 mg (group A) or a single dose of centchroman 30 mg, tetracycline 250 mg and one tablet containing 60 million lactic acid bacillus spores (group B). Tetracycline (250 mg three times daily) and lactic acid bacillus spores (one tablet three times daily) were continued for 3 days. Serial blood samples were collected and analysed by high performance liquid chromatography. The pharmacokinetic parameters were compared with the control data reported previously from this laboratory.

RESULTS

Coadministration of tetracycline yielded significantly higher maximum plasma concentrations (C(max)) [35%] and a shorter time to reach C(max) (t(max)) values for centchroman (42%) than those obtained in the control group of females (p < 0.05). Inclusion of lactic acid bacillus spores in the regimen resulted in similar effects with increased C(max) (47%) and area under the concentration-time curve from time zero to infinity (34%) of centchroman (p < 0.05) with a significant decrease in t(max). Other parameters such as half-life, apparent clearance, apparent volume of distribution and mean residence time of centchroman were not affected by either of the treatments.

CONCLUSIONS

The apparent effects of either of the regimens on centchroman pharmacokinetics seem to be of little clinical relevance in terms of increased rate or extent of availability. It can be concluded that this tetracycline-containing regimen is unlikely to alter the contraceptive efficacy of centchroman in humans.

Age- and sex-related reference values for serum insulin concentration and its biological determinants in a French healthy population. The STANISLAS cohort

Insulin is involved in coronary heart disease through diabetes and metabolic syndrome. A great deal is known about insulin and its correlates, as well as factors related to changes in insulin. However, few studies consider the broad variety of correlates simultaneously. Therefore, the aims of the present study were to characterize the main factors of biological variation affecting serum insulin concentration and to establish reference limits of insulinemia in a presumably healthy French population. Insulin was measured using a microparticular enzymatic immunoassay. A total of 646 subjects aged 11–58 years from the STANISLAS cohort and divided into four groups of 162 males, 157 females, 163 boys and 164 girls, were included in the statistical analyses. In the whole population, serum insulin concentration varied from 0.80 to 54.60 µU/ml. Significant factors affecting insulin were age, gender, body mass index and glucose, in addition to alanine aminotransferase and high-density lipoprotein cholesterol in men, triglycerides and oral contraceptive use in women, and alkaline phosphatase in girls.

In summary, we presented biological correlates of insulin in both healthy French male and female adults and children/adolescents and determined reference limits for insulin for each group. These results will contribute to a better interpretation of insulin data in further studies and laboratory investigations.

Serum levels of citalopram and its main metabolites in adolescent patients treated in a naturalistic clinical setting

The prescribing of selective serotonin reuptake inhibitors for adolescents is extensive despite the fact that there are few pharmacokinetic (PK), efficacy, safety, or tolerability studies on this group. This study reports the PK findings from two trials in adolescents treated with citalopram (CIT) in naturalistic clinical settings: one retrospective and one prospective. The aim of our study was to describe serum concentrations of CIT, desmethylcitalopram (DCIT), and didesmethylcitalopram (DDCIT) (trough values in steady state) in adolescents in relation to daily dose and clinical information obtained from therapeutic drug monitoring request forms. Altogether, 44 patients younger than 21 years were scrutinized using this combined open-label approach. The main findings were that (1) there was a pronounced interindividual variability of serum CIT, DCIT, and DDCIT concentrations in all doses prescribed, in agreement with previous studies on adults; on correcting for dose, the coefficient of variance was about 50% for CIT, DCIT, and DDCIT; (2) the transformation of CIT to DCIT and of DCIT to DDCIT was similar within the dose range 20 to 60 mg/day; (3) there was a difference between the sexes on comparing the dose-corrected concentrations of CIT and DCIT, with girls presenting significantly higher values than boys; and (4) there was a strong dose-serum concentration relationship in three identified subgroups of adolescents: (a) nonsmokers (CIT, r(2) = 0.71; DCIT, r(2) = 0.81), (b) girls not taking oral contraceptives (CIT, r(2) = 0.75; DCIT, r(2) = 0.71,), and (c) girls in the last 14 days of the menstrual cycle (CIT, r(2) = 0.68; DCIT, r(2) = 0.64). In summary, the present study tentatively supports influences of sex, oral contraceptives, and smoking habits on the disposition of CIT in younger patients. Hence, future studies on CIT should assess these parameters.

Tentative guidelines and practical suggestions to avoid venous thromboembolism during oral contraceptive therapy

Oral contraceptive therapy (OCT) is widely used in the world. It is usually safe and effective but side effects are occasionally seen. Venous thromboembolism is one of the most feared side effects. To avoid this complication adequate guidelines are needed. These have to take into account family history, personal history, and suitable laboratory investigations. The presence of an idiopathic venous thrombosis in the family or in the personal history is of paramount importance. However it is often difficult to ascertain whether a venous thrombosis is idiopathic or not. Even when there is doubt, a coagulation study should be carried out. An adequate coagulation study in this case should include at least an evaluation of antithrombin, protein C, and protein S. A search for homozygosity of factor V Leiden appears advisable. These defects represent absolute contraindications to the use of OCT. Relative contraindications may be represented by other minor coagulation disorders such as heterozygous factor V Leiden, fibrinolysis defects, and a G-to-A 20210 prothrombin abnormality. Other noncoagulation-related conditions such as hypertension, liver damage, and obesity may represent absolute or relative contraindications to the use of OCT.

Is family history sufficient to identify women with risk of venous thromboembolism before commencing the contraceptive pill?

Oral contraceptives (OGs) increase risk of venous thromboembolic disease (VTE). The incidence of thomboembolic disease in healthy young women who are not taking OCs is 0.4-0.8/10,000, and in healthy young women using OCs, it is 3-4/10,000. To assess whether a family history of thromboembolism is a suitable tool to identify women who should not be given OCs, 50 women who suffered a VTE while taking OCs were studied. Only 16% of these women had family history which is why in our opinion, it is not a sufficient safeguard to recommending the use of OCs.

Non-protein bound dienogest in serum and salivary dienogest in women taking the oral contraceptives Certostat and Valette

Dienogest (17 alpha-cyanomethyl-17-hydroxy-4,9-estradien-3-one) is the progestagen component of the oral contraceptives Certostat and Valette. In contrast to other 19-norsteroid progestagens like levonorgestrel, norethisterone, gestodene and 3-ketodesogestrel, dienogest does not bind to sexual hormone binding globulin (SHBG). The absent binding to SHBG results in a high portion of free, non-protein bound dienogest in serum. In female volunteers taking the oral contraceptives Certostat and Trisiston, the part of non-protein bound dienogest and levonorgestrel, respectively, in serum was determined by the method of centrifugal ultrafiltration. The portion of free dienogest was found to be 9.55 +/- 0.95% (m +/- SD, n = 13) of total serum dienogest. Free levonorgestrel constituted 0.97 +/- 0.14% (n = 12) of total serum levonorgestrel. In an investigation with 47 female volunteers taking Certostat, serum total dienogest was quantified by a specific radioimmunoassay and free dienogest in serum by centrifugal ultrafiltration. In the serum samples with dienogest concentrations in the range of 4.1-57.7 ng/ml, the part of free, non-protein bound dienogest was found to be 8.90 +/- 0.54% of serum total dienogest. There is a high correlation between serum total dienogest and free dienogest (r = 0.989). In another investigation with 20 female volunteers taking the contraceptive Valette, serum total dienogest and salivary dienogest were quantified by radioimmunoassay and free dienogest in serum by centrifugal ultrafiltration. In the serum samples with dienogest concentrations in the range of 7.5-50.6 ng/ml, the part of free, non-protein bound dienogest was 8.78 +/- 0.77% of serum total dienogest. Salivary dienogest constituted 7.99 +/- 0.94% of serum total dienogest showing a high correlation with serum free dienogest (r = 0.953) and serum total dienogest (r = 0.958). The high portion of non-protein bound compound in serum is a characteristic pharmacokinetic feature of dienogest.

Oral contraceptives can cause falsely low vitamin B(12) levels

Serum vitamin B(12) radioimmunoassays may give falsely low results in patients with folate deficiency, multiple myeloma, megadose of vitamin C and following radioisotope organ scan. We evaluated 10 consecutive healthy women on oral contraceptives (OC) who had falsely low vitamin B(12) levels, as reflected by normal urine methylmalonic acid and plasma homocysteine. After 1-month cessation of OCs, vitamin B(12) returned to the normal range in all women. Transcobalamin I (TCI) blood level was decreased in 60% of patients. OCs may cause temporary low vitamin B(12) blood levels of no clinical significance that can be associated with low TCI levels

Genetic regulation of plasma levels of vitamin K-dependent proteins involved in hematostatis: results from the GAIT Project. Genetic Analysis of Idiopathic Thrombophilia

Vitamin K-dependent proteins play a critical role in hemostasis. We have analysed the genetic and environmental correlations between measures of several vitamin K-dependent proteins in 21 Spanish extended families, including 397 individuals. Plasma functional levels of factors II, VII, IX, X, protein C and functional protein S were assayed in an automated coagulometer. Antigenic levels of total and free protein S were measured using an ELISA method. A maximum likelihood-based covariance decomposition analysis was used to assess the heritability of each trait and the genetic and environmental correlations between all possible pairs. All of the plasma levels had a significant genetic component (heritability) ranging from 22% to 52% of the phenotypic variance. Among the 28 possible pairs of genetic correlations, 18 were significant at a level of p < 0.05 and six exhibited a p-value between 0.05 and 0.10. Positive environmental correlation was observed for 25 of the pairs (p < 0.05). We conclude that genetic effects account for a large proportion of the observed phenotypic variation in vitamin K-dependent proteins. Some of the genes appear to pleiotropically influence all of these traits, since most pairs of phenotypes exhibit significant genetic correlation. However, since these phenotypes show a high degree of environmental correlation, it is also likely that the same environmental factors influence them co-jointly.

Determination of gestrinone in human serum by liquid chromatography--electrospray tandem mass spectrometry

A rapid, sensitive and specific high-performance liquid chromatography-electrospray tandem mass spectrometric method has been developed for the determination of gestrinone (R 2323) in human serum using mifepristone (RU 486) as an internal standard. R 2323 was extracted from human serum by an ether extraction procedure. Multiple reaction monitoring was used to detect R 2323 and RU 486. The calibration curve was linear over the range of 3.5-177 ng/ml (r2 > or =0.99) with the limitation of detection of 0.8 ng/ml. The intra-day precision and accuracy, expressed as C.V. and RE, ranged from 2.3-13.7 to -4.8-3.0%. The inter-day precision and accuracy ranged from 5.5-14.8 to -6.7-3.1%. The mean recovery was 91.0% for R 2323, and 90.6% for the internal standard. The method was successfully applied to the pharmacokinetic study of R 2323.

Pharmacodynamics of oestrogens and progestogens

The ovaries cyclically secrete estradiol and progesterone. Cyclic ovarian estradiol secretion is associated with a bone-saving and vascular protection effect. Endogenous progesterone does not modify the vasodilator effect of oestrogens. At physiological concentrations, the natural sex steroids have low antigonadotropic effects. More potent synthetic derivatives with more antigonadotropic effects were synthesized in the 1950s. After the menopause, there is no longer any need to use hormonal steroids as antigonadotropics. In addition, vascular contraindications are more common in an older population. Contraceptive steroids (particularly ethinyl estradiol) are therefore rarely used. The oestrogen that is most widely prescribed for post-menopausal replacement is a complex formulation of conjugated oestrogens of equine origin that is administered orally in a single daily dose. Improvements in hormone replacement therapy may result from the use of parenteral estradiol (providing sufficient doses are reached) and of a progestogen chemically more similar to progesterone.

Measurement of antithrombin activity by thrombin-based and by factor Xa-based chromogenic substrate assays

Functionally active antithrombin can be quantified by chromogenic substrate assays utilizing the heparin cofactor activity of antithrombin and the inhibition rates of thrombin or of activated factor X (FXa). Thrombin-based assays but not FXa-based assays may overestimate the antithrombin activity due to their sensitivity toward heparin cofactor II. We focused on the question whether an overestimation of antithrombin activity by thrombin-based assays involves the risk of misdiagnosing antithrombin-deficient individuals as being non-deficient. We determined antithrombin using two thrombin-based assays and one FXa-based assay in 27 plasma samples from patients with acquired antithrombin deficiency spiked with lepirudin, in antithrombin-deficient plasma and in mixtures of antithrombin-deficient plasma and normal plasma. We also measured antithrombin in healthy subjects, in patients with inherited and acquired antithrombin deficiency and in patients under high-dose heparin treatment. At therapeutic final concentrations of lepirudin, antithrombin activities were considerably overestimated by the thrombin-based assays but not by the FXa-based assay. The residual antithrombin activities in antithrombin-deficient plasma determined by the thrombin-based assays were markedly higher than the corresponding values obtained with the FXa-based assay. The thrombin-based assays also overestimated antithrombin activity in patients under high-dose heparin. However, the degree of overestimation in the range between 50 and 100 IU/dl was too low to misidentify individuals with inherited or acquired antithrombin deficiency as normal. We conclude that functionally active antithrombin can be reliably determined using FXa-based chromogenic substrate assays in all settings examined. Thrombin-based assays must not be used in patients under treatment with hirudin or other direct thrombin inhibitors.

Effect of troglitazone on the pharmacokinetics of an oral contraceptive agent

Fifteen healthy women participated in a study to determine the effect of multiple doses of troglitazone on the pharmacokinetics of Ortho-Novum 1/35 (35 micrograms ethinyl estradiol [EE] and 1 mg norethindrone [NE]). Participants received three cycles (21 days each of active drug followed by 7 days without medication) of Ortho-Novum. During the third cycle, participants also received troglitazone 600 mg qd for 22 days. Pharmacokinetic profiles of EE and NE were determined on day 21 of the second and third cycles. Progesterone and sex hormone binding globulin (SHBG) levels were also measured. Troglitazone decreased EE Cmax and AUC(0-24) by 32% and 29%, respectively. Likewise, troglitazone decreased NE Cmax and AUC(0-24) by 31% and 30%, respectively. Plasma SHBG concentrations increased from 113 nmol/L during cycle 2 to 220 nmol/L during cycle 3. Troglitazone reduced plasma unbound AUC for NE by 49%. Serum progesterone levels were lower than 1.5 ng/mL on all occasions. Thus, coadministration of troglitazone and Ortho-Novum decreases the systemic exposure to EE and NE. A higher dose of oral contraceptive or an alternate method of contraception should be considered for patients treated with troglitazone.

Lack of effect of hormonal treatment and smoking on cytokeratin expression in buccal mucosa

Differences in cytokeratin expression of clinically normal buccal mucosa were studied in 50 healthy women by indirect immunofluorescence staining with monoclonal antibodies. The subjects were divided into four groups: control group (N = 18), smokers (N = 8), oral contraceptive users (N = 8) and smokers receiving oral contraceptives (N = 16). Our findings indicate that cytokeratin expression in noncornified stratified epithelium is not influenced by smoking or oestradiol/progesterone treatment. Only cytokeratin No. 19 showed variable patterns of expression but the differences could not be ascribed to smoking or contraceptives. Cytokeratin No. 19 gave a positive reaction in the basal and suprabasal layers in 34 subjects (68%). In 9 (18%) specimens, the staining was positive in the basal cells and showed a positive heterogeneous cytoplasmic reaction in the suprabasal cells. Interestingly, cytokeratin No. 7 was recognized in all epithelial cells except the basal cells. Our results suggest that changes in the serum oestradiol levels do not affect the cytokeratin pattern in buccal mucosa.

[Estrogens. Contraceptive therapy]

To evaluate the competitive molecular phenomenon of Ethynyl-Estradiol (EE-2) from contraceptive formulations against the endogenous Estradiol (E-2) at the intra and the extracellular compartments, plasma and endometrial samples were simultaneously obtained on different days of the pseudomenstrual cycle from oral contraceptive users under EE-2+ Norgestrel (30 micrograms/+ 500 micrograms) and EE-2+ Norethindrone (50 micrograms + 1.0 mg) in order to quantify EE-2 & E-2. When measuring both molecules it was shown that the chronic administration of steroids regardless of the pharmacological action of the progestin component the lower content of EE-2 (30 micrograms) does not compete substantially at the circulating level permitting the cyclic fashion of the natural estradiol while at the endometrial compartment such phenomenon is not seen thus, a local infertility effect should be reconsidered to anticipate a different approach in the future of contraception.

Lansoprazole does not affect the bioavailability of oral contraceptives

The effects of the proton pump inhibitor lansoprazole on the bioavailability of a low-dose oral contraceptive (OC), containing 0.03 mg ethinyloestradiol (EE) and 0.15 mg levonorgestrel (LNG), were investigated. Twenty-four healthy females (aged 19-35 years; weight 60.6 +/- 7.1 kg) participated in a multiple-dose, placebo-controlled, randomized two-way cross-over study. All subjects received the OC over 2 full menstrual cycles from day 1 to day 21 separated by a drug-free interval of 7 days. Lansoprazole (60 mg day-1) or placebo was coadministered for 3 weeks each. Plasma concentrations of EE and LNG were determined by GC-MS. The 90% confidence intervals for ratios of Cmax and AUC after log transformation of both EE and LNG ranged between 91 and 111%, indicating that lansoprazole did not affect the bioavailability of EE and LNG.

Oral contraceptives. Are drug interactions of clinical significance?

There is a large quantity of literature on drug interactions with oral contraceptive (OC) steroids although their incidence is not known. The potential clinical significance of some interactions makes it important for all prescribing doctors and dentists to have some knowledge of the topic. Interactions may be divided into those in which OC effectiveness is impaired, causing breakthrough bleeding or pregnancy, those in which OC activity is enhanced by other drugs and those in which OCs interfere with the metabolism or activity of other therapeutic agents. Consideration of their pharmacology indicates that impairment of OC effect is most likely to be due to interference with ethinylestradiol. This is because this compound is sulphated in the gut wall, hydroxylated and glucuronidated in the liver, and undergoes enterohepatic recirculation. The progestogens are only metabolised in the liver and have no significant enterohepatic recirculation. Protein binding interactions are rarely of clinical importance. OC plasma concentrations may be reduced by induction of hepatic metabolism in the case of griseofulvin, rifampicin (rifampin) and several anticonvulsant drugs; valproic acid (sodium valproate) does not have this effect. Antibiotics may interfere with enterohepatic recirculation of ethinylestradiol and reduce plasma levels of active hormone. This is probably only of significance in a subgroup of women who may sometimes be suspected on history, but cannot be identified by any diagnostic test. Reasons for differences between case reports and formal studies of interactions with antibiotics are discussed. Plasma concentrations of ethinylestradiol may be increased by ascorbic acid (vitamin C) and paracetamol (acetaminophen) which compete with it for sulphation in the gut wall. Theoretically, problems may arise if these agents are stopped suddenly. Imidazole antifungal agents can inhibit ethinylestradiol metabolism and increase its plasma concentrations but the clinical significance of this is unknown. OCs have been shown to inhibit metabolism of many therapeutic drugs and increase their plasma concentrations. This may be of clinical significance in the case of benzodiazepines which are hydroxylated in the liver, but clinical effects are less certain with the other agents. OCs may induce metabolism of other drugs which are glucuronidated, including some benzodiazepines and analgesics. The clinical significance of this type of interaction is also unknown. It is suggested that all prescribers should remember to ask about OCs when taking a drug history and to consider the possibility of interactions with other drugs.

Pharmacokinetics of the contraceptive steroids levonorgestrel and gestodene after single and multiple oral administration to women

Little is known about the pharmacokinetics of the two progestins levonorgestrel and gestodene during long-term administration compared with single-dose pharmacokinetics. The predictive value of single-dose administration for the pharmacokinetic behavior of a progestin during long-term treatment was investigated for two triphasic oral contraceptives. One contained levonorgestrel and the other gestodene, each in combination with ethinyl estradiol. In eight Japanese women who received the levonorgestrel-containing formulation over a treatment cycle, steady-state trough levels of levonorgestrel were higher than those obtained by computer simulation based on single-dose administration. An analogous observation was made in a group of 10 white women who received the gestodene-containing formulation. A close correlation between gestodene and sex hormone-binding globulin concentrations was demonstrated for eight subjects; the other two patients already had initially high sex hormone-binding globulin levels. Ethinyl estradiol-induced production of sex hormone-binding globulin seems to be a major factor that contributes to the accumulation of the two progestins in the plasma. Computer simulation, based on single-dose pharmacokinetics, allows an estimation of this contribution.

Pharmacokinetics of oral contraceptive steroids in Egyptian women: studies with Ovral, Nordette and Norminest

Plasma concentration profiles and pharmacokinetic parameters have been obtained following single dose administration of three commonly used oral contraceptive steroid preparations, Ovral, Nordette and Norminest to Egyptian women. The constituents of the preparations are as follows: Ovral (50 micrograms ethinyloestradiol, EE2 and 500 micrograms levonorgestrel, LNG); Nordette (30 micrograms EE2 and 150 micrograms LNG); and Norminest (35 micrograms EE2 and 500 micrograms norethisterone, NOR). Peak plasma concentrations of EE2 ranged between 116-160 pg ml-1 for Ovral, 55-78 pg ml-1 for Norminest and 30-70 pg ml-1 for Nordette. There was no significant difference in half-life (t1/2), oral clearance (CL) or apparent volume of distribution (Vd). The relative values of the area under the plasma concentration-time curve (AUC) reflected well the different amounts of oestrogen in each preparation. There was no significant difference in t1/2, CL or Vd for LNG in the 2 preparations containing this progestogen. The mean AUC following Nordette (150 micrograms LNG) was 40% of that following Ovral (500 micrograms LNG; p less than 0.001). Comparing pharmacokinetic parameters for the same dose of LNG (Ovral) and NOR (Norminest) showed the AUC to be decreased and CL and Vd increased in the latter group. The study indicates that the kinetic profile of the OCS in healthy Egyptian women are similar to other ethnic populations.

Effect of dose on the pharmacokinetics of levonorgestrel in the rat during the rapid elimination phase following subcutaneous administration

Adult female rats were given a single, subcutaneous injection of 8, 16 or 32 micrograms of levonorgestrel (LNG). Blood samples were collected at various time intervals and serum concentrations of LNG were determined by radioimmunoassay. The patterns of temporal decline in LNG concentrations in the three dose groups indicated that the pharmacokinetics of LNG during the post-absorptive, rapid-elimination (beta) phase in the rat may be dose-dependent. Half-life, Co and AUC increased with the dose and -beta decreased as the dose increased. Mathematical relationships have been presented which can be used to predict the four parameters as well as concentrations of LNG at any given time after subcutaneous administration during the beta-phase for a given dose in the range of 8-32 micrograms. Significance of dose-dependent pharmacokinetic studies is discussed.

Pharmacokinetics of oral contraceptive steroids following the administration of the antimalarial drugs primaquine and chloroquine

The effects of a single dose of two antimalarial drugs chloroquine (CQ) and primaquine (PQ) on the pharmacokinetics of a combined oral contraceptive (O.C.) have been studied in volunteers. Each woman was studied on 3 separate occasions over 3 cycles and plasma concentrations of ethinyloestradiol (EE2) and levonorgestrel were measured by radioimmunoassay following administration of a single dose of O.C. (30 micrograms EE2 + 150 micrograms levonorgestrel) in the absence and presence of the antimalarial drugs (PQ, 45 mg; CQ, 300 mg). Neither CQ or PQ given 1 h before the O.C. had any significant effect on plasma concentrations of EE2 or levonorgestrel or on any pharmacokinetic parameter determined. There is therefore, no evidence that CQ or PQ interfere with the hepatic handling of O.C.'s. This is in contrast to previously reported inhibitory effects of PQ on the metabolism of antipyrine.

Plasma levels of levonorgestrel, gestodene, norethisterone and cyproterone acetate on single-dose subcutaneous administration in oily solution in the rat, beagle and rhesus monkey

This report describes the pharmacokinetics of levonorgestrel, gestodene, norethisterone and cyproterone acetate following subcutaneous administration of oily solutions in the rat, beagle dog and rhesus monkey. The plasma levels of the progestogens were measured by means of specific radioimmunoassays. Half-lives calculated for the disposition process of a particular metabolically unchanged drug in plasma revealed marked differences in different animal species. Furthermore, comparison of the different progestogens showed large variations in this parameter in all the animal species. It became obvious that there are physico-chemical properties as well as metabolic rate limitations effecting the release and elimination of synthetic progestogens administered in oily solution. The results are compared with the half-lives of these progestogens administered intravenously as reported previously. A prolongation of half-life as a result of the depot effect of subcutaneous administration was demonstrated for all the progestogens in the rat, the beagle dog and the rhesus monkey.

Plasma renin substrate, renin activity, and aldosterone levels in a sample of oral contraceptive users from a community survey

Fasting plasma renin substrate (PRS), plasma renin activity (PRA), plasma aldosterone (PA), and blood pressure (BP) levels were measured from 212 apparently healthy normotensive nonpregnant white women aged 21 to 39 years, selected on the basis of oral contraceptive (OC) use of nonuse in 1976 following a community survey in East Boston. The mean PRS level was 7118 ng/dl among OC users and 1935 ng/dl among nonusers (p less than 0.0001). In contrast, mean PRA was 2.9 ng of angiotensin 1 per milliliter per hour among users and 3.0 ng of angiotensin l/ml/hr among nonusers (p = NS); mean PA levels were 26.2 ng/dl and 25.4 ng/dl, respectively (p = NS). Mean systolic BPs were 113.8 mm Hg among current OC users and 111.2 mm Hg among nonusers (p = 0.078); diastolic BPs were 68.5 and 68.9, respectively (p = NS). These data indicate a greater than three-fold increase in PRS among current OC users compared to nonusers, with virtually identical PRA and PA levels. The data indicate that normotensive women using OCs maintain normal PRA and PA levels despite marked elevations in PRS.

The effects of ampicillin on oral contraceptive steroids in women

1 Thirteen women taking long term oral contraceptive steroids were studied while taking ampicillin (500 mg three times daily) and compared to a control cycle while not taking ampicillin. 2 There were no significant changes in the plasma concentrations of ethinyloestradiol, levonorgestrel, follicle stimulating hormone or progesterone, although lower concentrations of ethinyloestradiol were noted in two women. 3 We conclude that most patients taking oral contraceptive steroids do not need to take alternative contraceptive precautions while taking ampicillin.

alpha 2-Antiplasmin and alpha 2-macroglobulin--the main inhibitors of fibrinolysis--during the menstrual cycle, pregnancy, delivery, and treatment with oral contraceptives

alpha 2-Antiplasmin and alpha 2-macroglobulin have been studied during the menstrual cycle, pregnancy and parturition in healthy women, and during use of various types of contraception in both healthy and diabetic women, and compared with a reference group of healthy men and women. alpha 2-Antiplasmin showed a slight sex difference, with higher values in women. The luteal phase of the menstrual cycle showed slightly higher values than the other phases. alpha 2-Antiplasmin increased during pregnancy, decreased (probably due to consumption) during labor and increased again in the puerperium. Treatment with neither combined contraceptive pills nor low dose progestogen pills gave any changes in alpha 2-antiplasmin. alpha 2-Macroglobulin showed low values during menstruation. The increase during pregnancy and treatment with combined contraceptive pills is in accordance with earlier findings. It is concluded that synthesis and metabolism of alpha 2-antiplasmin are under hormonal influence. The role of alpha 2-antiplasmin in the decreased fibrinolysis in pregnancy is discussed.

Measurement by isotope dilution mass spectrometry of 17 alpha-ethynyloestradiol-17 beta and norethisterone in serum of women taking oral contraceptives

The highly specific and accurate technique of isotope dilution mass spectrometry has been used for the measurement of 17 alpha-ethynyloestradiol-17 beta and norethisterone in serum. Serum samples were obtained from female volunteers who received 2.5 mg lynestrenol and 50 micrograms 17 alpha-ethynyloestradiol-17 beta in two different galenical preparations. The determination of total 17 alpha-ethynyloestradiol-17 beta (conjugated and non-conjugated) was carried out by the following procedure: (1) adsorption of the steroids from 1 ml serum to Amberlite XAD-2; (2) enzyme hydrolysis of the conjugated steroid; (3) addition of 1 ng [6,7-3H2] 17 alpha-ethynyloestradiol-17 beta as internal standard; (4) column chromatography on Sephadex LH 20; (5) derivative formation with heptafluorobutyric anhydride; (6) isotope dilution mass spectrometry at m/z 474 and 478 using a glass capillary gas-liquid chromatography column. For the measurement of norethisterone, which is the major metabolite of lynestrenol, 1 ng [7-3H]norethisterone was added to 0.5 ml serum. The labelled and the non-labelled steroids were extracted and purified by column chromatography on Sephadex LH 20. The norethisterone was reacted to form the 3-enol-17 beta-trimethylsilyl ether of norethisterone and [3H]norethisterone. For isotope dilution mass spectrometry the derivative was injected into the glass capillary column which was coupled to the mass spectrometer. The instrument was adjusted to m/z 442 and 444, corresponding to the molecular ions of the ether derivatives of norethisterone and [7-3H]norethisterone. Accuracy was achieved by the use of highly specific technique of mass spectrometry and the exact control of recovery using the isotope dilution principle. The precision was 4.5% (CV) for the determination of 17 alpha-ethynyloestradiol-17 beta and 2.5% (CV) for norethisterone. The lower limit of detection was at 20 pg ml-1 for both methods.

A radioimmunoassay for norethindrone (NET): measurement of serum NET concentrations following ingestion of NET-containing oral contraceptive steroids

A sensitive and reliable radioimmunoassay (RIA) for the measurement of norethindrone (NET) in serum has been established employing anti-11 alpha-hydroxynorethindrone 11-hemisuccinyl-bovine serum albumin serum in conjunction with norethindrone-3-(0-carboxymethyl) oximino-[125I]-iodohistamine. Of a number of ring A reduced NET metabolites, only 17 beta-hydroxy-17 alpha-ethinyl-5 beta-estran-3-one (43%) and 17 alpha-ethinyl-5 alpha-estrane-3 beta, 17 beta-diol (15.7%) cross-reacted appreciably in this RIA. Ethinyl estradiol (EE2) and mestranol (MEE2) exhibited cross-reactions of only 1.1 and 0.4%, respectively. Serum NET levels were measured in four groups of 3 women, each ingesting either 1 mg NET plus 0.05 mg MEE2 (Norinyl 1 + 50 or Ortho Novum 1/50), 0.5 mg NET plus 0.035 mg EE2 (Brevicon) or only 0.35 mg NET (Micronor) daily for 5 consecutive days. Peak serum NET levels were observed within 1/2 to 4 hours after oral intake and fell precipitously thereafter. After reaching a maximum, serum NET concentrations declined in a manner consistent with at least two disposition phases. The average half-life for the first disposition phase was 2.3, 3.4, 3.9 and 4.4 hours in subjects ingesting Norinyl 1 + 50, Ortho Novum 1/50, Brevicon and Micronor, respectively. Peak and 3-hour post-ingestion serum NET concentrations were dose-related but showed considerable subject-to-subject variations. Following discontinuation of tablet intake, serum NET levels remained detectable (greater than 0.05 ng/ml) for at least 5 days in all 3 women who had taken Ortho Novum 1/50, but in none of the other 9 volunteers. These results suggest that different preparations of identical doses and combinations of oral contraceptive steroids may yield different serum NET profiles. However, due to considerable subject-to-subject variations, larger numbers of subjects are required for a conclusive investigation.

[Immunological dtermination of at. III (author's transl)]

We have effectuated immunologically determination of At. III in serum and plasma into two groups of patients: 1) constituted of 10 subjects which never take oral hormone contraceptives; 2) constituted of 22 subjects who are taking OHC; for various time period. The results indicating that a difference exist between serum and plasma At. III concentration, ad this difference reaches to 30%. In this series of data the At. III levels was normals.

A simple method for the determination of free cortisol in plasma, with normal levels in men and women, including women taking low oestrogen contraceptives

A small scale equilibrium dialysis method for the measurement of the non-protein bound cortisol in plasma is described. Dialysis is carried out in PTFE cells against an isosmolar Hepes buffer, equilibration occurring within 18 hours. Inter-assay variation was found to be approximately 6%. Samples taken from normal males and females and from oestrogen-treated females were analysed and the results compared with published levels. A significant difference in both the total and free cortisol levels was found between the normals and oestrogen-treated females.