2.1 How to take Natazia

To achieve maximum contraceptive effectiveness, Natazia must be taken exactly as directed. Take one tablet by mouth the same time every day. Tablets must be taken in the order directed on the blister pack. Tablets should not be skipped or intake delayed by more than 12 hours. For patient instructions for missed pills, see FDA-Approved Patient Labeling.

2.2 How to start Natazia

Instruct the patient to begin taking Natazia on Day 1 of her menstrual cycle (that is, the first day of her menstrual bleeding) [see FDA-Approved Patient Labeling]. Instruct the patient to use a non-hormonal contraceptive as back-up during the first 9 days.

For postpartum women who do not breastfeed or after a second trimester abortion, Natazia may be started no earlier than 4 weeks postpartum. Recommend use of a non-hormonal back-up method for the first 9 days. When combined oral contraceptives (COCs) are used during the postpartum period, the increased risk of thromboembolic disease associated with the postpartum period must be considered. The possibility of ovulation and conception before starting COCs should also be considered.

If the patient is switching from a combination hormonal method such as:

• • Another pill
  • Vaginal ring
  • Patch
• Instruct her to take the first dark yellow pill on the first day of her withdrawal bleed. She should not continue taking the pills from her previous birth control pack. If she does not have a withdrawal bleed, rule out pregnancy before starting Natazia.
• If she previously used a vaginal ring or transdermal patch, she should start using Natazia on the day the ring or patch is removed.
• Instruct the patient to use a non-hormonal back-up method such as a condom or spermicide for the first 9 days.

If the patient is switching from a progestin-only method such as a:

• • Progestin-only pill
  • Implant
  • Intrauterine system
  • Injection
• Instruct her to take the first dark yellow pill on the day she would have taken her next progestin-only pill or on the day of removal of her implant or intrauterine system or on the day when she would have had her next injection.
• Instruct the patient to use a non-hormonal back-up method such as a condom or spermicide for the first 9 days.

2.3 Advice in case of Gastrointestinal Disturbances

In case of severe vomiting or diarrhea, absorption may not be complete and additional contraceptive measures should be taken. If vomiting or diarrhea occurs within 3-4 hours after taking a colored tablet, this can be regarded as a missed tablet. [See FDA-Approved Patient Labeling.]

5.1 Thrombotic and Other Vascular Events

Stop COCs if an arterial or deep venous thrombotic (VTE) event occurs. Although the use of COCs increases the risk of venous thromboembolism, pregnancy increases the risk of venous thromboembolism as much or more than the use of COCs. The risk of venous thromboembolism in women using COCs is 3 to 9 per 10,000 woman-years. The excess risk is highest during the first year of use of a COC. Use of COCs also increases the risk of arterial thromboses such as strokes and myocardial infarctions, especially in women with other risk factors for these events. The risk of thromboembolic disease due to oral contraceptives gradually disappears after COC use is discontinued.

If feasible, stop COCs at least 4 weeks before and through 2 weeks after major surgery or other surgeries known to have an elevated risk of thromboembolism.

Start COCs no earlier than 4 weeks after delivery, in women who are not breastfeeding. The risk of postpartum thromboembolism decreases after the third postpartum week, whereas the risk of ovulation increases after the third postpartum week.

COCs have been shown to increase both the relative and attributable risks of cerebrovascular events (thrombotic and hemorrhagic strokes), although, in general, the risk is greatest among older (>35 years of age), hypertensive women who also smoke. COCs also increase the risk for stroke in women with other underlying risk factors.

Oral contraceptives must be used with caution in women with cardiovascular disease risk factors. Stop COCs if there is unexplained loss of vision, proptosis, diplopia, papilledema, or retinal vascular lesions. Evaluate for retinal vein thrombosis immediately. [See Adverse Reactions (6).]

5.2 Carcinoma of the Breasts and Reproductive Organs

Women who currently have or have had breast cancer should not use COCs because breast cancer is a hormonally-sensitive tumor.

There is substantial evidence that COCs do not increase the incidence of breast cancer. Although some past studies have suggested that COCs might increase the incidence of breast cancer, more recent studies have not confirmed such findings.

Some studies suggest that COCs are associated with an increase in the risk of cervical cancer or intraepithelial neoplasia. However, there is controversy about the extent to which these findings may be due to differences in sexual behavior and other factors.

Endometrial biopsies performed in a subset of subjects in a Phase 3 Natazia clinical trial did not reveal any unexpected or concerning findings for subjects taking COCs. [See Adverse Reactions (6.1).]

5.3 Liver Disease

Discontinue COCs if jaundice develops. Steroid hormones may be poorly metabolized in patients with impaired liver function. Acute or chronic disturbances of liver function may necessitate the discontinuation of COC use until markers of liver function return to normal and COC causation has been excluded.

Hepatic adenomas are associated with COC use. An estimate of the attributable risk is 3.3 cases/100,000 COC users. Rupture of hepatic adenomas may cause death through intra-abdominal hemorrhage.

Studies have shown an increased risk of developing hepatocellular carcinoma in long-term (> 8 years) COC users. However, the attributable risk of liver cancers in COC users is less than one case per million users.

Oral contraceptive-related cholestasis may occur in women with a history of pregnancy-related cholestasis. Women with a history of COC-related cholestasis may have the condition recur with subsequent COC use.

5.4 High Blood Pressure

For women with well-controlled hypertension, monitor blood pressure and stop COCs if blood pressure rises significantly. Women with uncontrolled hypertension or hypertension with vascular disease should not use COCs.

An increase in blood pressure has been reported in women taking COCs, and this increase is more likely in older women and with extended duration of use. The incidence of hypertension increases with increasing concentration of progestin.

5.5 Gallbladder Disease

Studies suggest a small increased relative risk of developing gallbladder disease among COC users.

5.6 Carbohydrate and Lipid Metabolic Effects

Carefully monitor prediabetic and diabetic women who are taking COCs. COCs may decrease glucose tolerance in a dose-related fashion.

Consider alternative contraception for women with uncontrolled dyslipidemia. A small proportion of women will have adverse lipid changes while on COCs.

Women with hypertriglyceridemia, or a family history thereof, may be at an increased risk of pancreatitis when using COCs.

5.7 Headache

If a woman taking COCs develops new headaches that are recurrent, persistent, or severe, evaluate the cause and discontinue COCs if indicated.

An increase in frequency or severity of migraine during COC use (which may be prodromal of a cerebrovascular event) may be a reason for immediate discontinuation of the COC. [See Adverse Reactions (6).]

5.8 Bleeding Irregularities

Breakthrough bleeding and spotting sometimes occur in patients on COCs, especially during the first three months of use. If bleeding persists or occurs after previously regular cycles, check for causes such as pregnancy or malignancy. If pathology and pregnancy are excluded, bleeding irregularities may resolve over time or with a change to a different COC.

Women who are not pregnant and use Natazia, may experience amenorrhea. Based on patient diaries, amenorrhea occurs in approximately 16% of cycles in women using Natazia. Pregnancy should be ruled out in the event of amenorrhea occurring in two or more consecutive cycles. Some women may encounter amenorrhea or oligomenorrhea after stopping COCs, especially when such a condition was pre-existent.

Based on patient diaries from three clinical trials evaluating the safety and efficacy of Natazia, 10-23% of women experienced intracyclic bleeding per cycle. A total of 38 subjects out of 2,266 (1.7%) discontinued due to metrorrhagia or irregular menstruation.

5.9 COC Use Before or During Early Pregnancy

Extensive epidemiological studies have revealed no increased risk of birth defects in women who have used oral contraceptives prior to pregnancy. Studies also do not suggest a teratogenic effect, particularly in so far as cardiac anomalies and limb-reduction defects are concerned, when taken inadvertently during early pregnancy. Oral contraceptive use should be discontinued if pregnancy is confirmed.

The administration of oral contraceptives to induce withdrawal bleeding should not be used as a test for pregnancy [see Use in Specific Populations (8.1)].

5.10 Emotional Disorders

Women with a history of depression should be carefully observed and the COC discontinued if depression recurs to a serious degree.

5.11 Interference with Laboratory Tests

The use of COCs may change the results of some laboratory tests, such as coagulation factors, lipids, glucose tolerance, and binding proteins. Women on thyroid hormone replacement therapy may need increased doses of thyroid hormone because serum concentrations of thyroid-binding globulin increase with use of COCs.

5.12 Monitoring

A woman who is taking COCs should have a yearly visit with her healthcare provider for a blood pressure check and for other indicated healthcare.

5.13 Drug Interactions

Women who take medications that are strong CYP3A4 inducers (for example, carbamazepine, phenytoin, rifampicin, and St. John’s wort) should not choose Natazia as their oral contraceptive while using these inducers and for at least 28 days after discontinuation of these inducers due to the possibility of decreased contraceptive efficacy. [See Drug Interactions (7.1) and Clinical Pharmacology (12.3).]

5.14 Other Conditions

In women with hereditary angioedema, exogenous estrogens may induce or exacerbate symptoms of angioedema. Chloasma may occasionally occur, especially in women with a history of chloasma gravidarum. Women with a tendency to chloasma should avoid exposure to the sun or ultraviolet radiation while taking COCs.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Contraception Studies

Two multicenter phase 3 clinical trials evaluated the safety and efficacy of Natazia for pregnancy prevention. Both were non-comparative, open-labeled, single-arm studies with a treatment duration up to 28 cycles. A total of 1,867 women aged 18–50 were enrolled and took at least one dose of Natazia. [See Clinical Studies (14.1).]

Adverse Reactions Leading to Study Discontinuation: 11.5% of the women discontinued from the clinical trials due to an adverse reaction; the most frequent adverse reactions leading to discontinuation were metrorrhagia and irregular menstruation (1.9%), acne (1.2%), headache and migraine (1.0%), and weight increase (0.7 %).

Common Treatment-Emergent Adverse Reactions (≥ 2%): headache (including migraines) (13.2%), metrorrhagia and irregular menstruation (8.0%), breast pain, discomfort or tenderness (6.6%), nausea or vomiting (6.5%), acne (3.9%) and increased weight (2.8%).

Serious Adverse Reactions: deep vein thrombosis, myocardial infarction, focal nodular hyperplasia of the liver, uterine leiomyoma, and ruptured ovarian cyst.

7.1 Effects of Other Drugs on Combined Hormonal Contraceptives

Interactions between oral contraceptives and other drugs may lead to breakthrough bleeding and/or contraceptive failure. The following interactions have been reported in the literature for COCs in general or were studied in clinical trials with Natazia.

CYP3A4 Inducers: Drugs or herbal products that induce certain enzymes, including CYP3A4, may decrease the effectiveness of COCs or increase breakthrough bleeding. Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include barbiturates, bosentan, felbamate, griseofulvin, oxcarbazepine, and topiramate. Counsel women to use an alternative method of contraception or a back-up method when moderate or weak enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer to ensure contraceptive reliability.

Dienogest is a substrate of cytochrome P450 (CYP) 3A4. Women who take medications that are strong CYP3A4 inducers (for example, carbamazepine, phenytoin, rifampicin, and St. John’s wort) should not choose Natazia as their oral contraceptive while using these inducers and for at least 28 days after discontinuation of these inducers due to the possibility of decreased contraceptive efficacy.

The effect of the CYP3A4 inducer rifampicin was studied in healthy postmenopausal women. Co-administration of rifampicin with estradiol valerate/dienogest tablets led to a 52 % and 83% decrease in the mean Cmax and AUC(0 –24hr), respectively, for dienogest and a 25% and 44% decrease in Cmax and AUC(0–24hr), respectively, for estradiol at steady state.

Strong CYP3A4 Inhibitors: Strong CYP3A4 inhibitors such as ketoconazole increased hormone serum concentrations. In a study investigating the effect of ketoconazole on dienogest and estradiol pharmacokinetics, co-administration with the strong CYP3A4 inhibitor ketoconazole resulted in a 186% increase of AUC (0 –24hr) at steady state for dienogest and a 57% increase for estradiol. There was also a 94% and 65% increase of Cmax at steady state for dienogest and estradiol when co-administered with ketoconazole.

Moderate CYP3A4 Inhibitors: The AUC (0–24hr) of dienogest and estradiol at steady state were increased by 62% and 33%, respectively, when co-administered with a moderate CYP3A4 inhibitor, erythromycin. There was also a 33% and 51% increase of Cmax at steady state for dienogest and estradiol, respectively, when co-administered with erythromycin.

Other known CYP.3A4 inhibitors like azole antifungals, cimetidine, verapamil, macrolides, diltiazem, antidepressants, and grapefruit juice may increase plasma levels of dienogest.

HIV Protease Inhibitors: Significant changes (increase or decrease) in the plasma levels of estrogen and progestin have been noted in some cases of co-administration of HIV protease inhibitors.

Antibiotics: There have been reports of pregnancy while taking hormonal contraceptives and antibiotics, but clinical pharmacokinetic studies have not shown consistent effects of antibiotics on plasma concentrations of synthetic steroids.

Consult the labeling of all concurrently-used drugs to obtain further information about interactions with hormonal contraceptives or the potential for enzyme alterations.

7.2 Effects of Combined Hormonal Contraceptives on Other Drugs

COCs containing ethinyl estradiol (or mestranol), may inhibit the metabolism of other compounds. COCs have been shown to significantly decrease plasma concentrations of lamotrigine, likely due to induction of lamotrigine glucuronidation. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary. Consult the labeling of the concurrently-used drug to obtain further information about interactions with COCs or the potential for enzyme alterations.

In vitro studies with human CYP enzymes did not indicate an inhibitory potential of dienogest at clinically relevant concentrations.

8.1 Pregnancy

Pregnancy category X. [See Contraindications (4) and Warnings and Precautions (5.9).]

8.3 Nursing Mothers

When possible, advise the nursing mother to use other forms of contraception until she has weaned her child. Estrogen-containing OCs can reduce milk production in breastfeeding mothers. This is less likely to occur once breastfeeding is well-established; however, it can occur at any time in some women. Small amounts of oral contraceptive steroids and/or metabolites are present in breast milk.

8.4 Pediatric Use

Safety and efficacy of Natazia have been established in women of reproductive age. Efficacy is expected to be the same for postpubertal adolescents under the age of 18 as for users 18 years and older. Use of this product before menarche is not indicated. [See Clinical Pharmacology (12.3).]

8.5 Geriatric Use

Natazia has not been studied in postmenopausal women and is not indicated in this population. [See Clinical Pharmacology (12.3).]

8.6 Renal Impairment

The pharmacokinetics of Natazia has not been studied in subjects with renal impairment, but an effect requiring dose adjustment is unlikely to be present [see Clinical Pharmacology (12.3)].

8.7 Hepatic Impairment

The pharmacokinetics of Natazia has not been studied in subjects with hepatic impairment. Steroid hormones may be poorly metabolized in patients with impaired liver function. Acute or chronic disturbances of liver function may necessitate the discontinuation of COC use until markers of liver function return to normal. [See Contraindications (4), Warnings and Precautions (5.3) and Clinical Pharmacology (12.3)]

8.8 Body Mass Index

The safety and efficacy of Natazia in women with a BMI of > 30 kg/m2 has not been evaluated. [See Clinical Pharmacology (12.3).]

12.1 Mechanism of Action

COCs lower the risk of becoming pregnant primarily by suppressing ovulation. Other possible mechanisms may include cervical mucus changes that inhibit sperm penetration and endometrial changes that reduce the likelihood of implantation.

12.2 Pharmacodynamics

The contraceptive effect of COCs is based on the interaction of various factors, the most important of which are the inhibition of ovulation and the changes in the cervical secretion. The estrogen in Natazia is estradiol valerate, a synthetic prodrug of 17ß-estradiol.

The progestin in Natazia is dienogest (DNG). DNG displays properties of 19-nortestosterone derivatives as well as properties associated with progesterone derivatives. [See Nonclinical Toxicology (13.2).]

Cardiac Electrophysiology

The effect of Natazia on QT prolongation was evaluated in a randomized, double-blind, positive (moxifloxacin 400 mg) and negative (placebo) controlled crossover study in healthy subjects. A total of 53 subjects were administered Natazia (containing 3 mg dienogest and 2 mg estradiol valerate), dienogest 10 mg, and placebo as once daily doses for 4 days, and moxifloxacin 400 mg as a single oral dose. The upper bound of the 90% confidence interval for the largest placebo-adjusted, baseline-corrected QTc based on Fridericia’s correction method (QTcF) was below 10 msec, the threshold for regulatory concern.

12.3 Pharmacokinetics

Absorption

After oral administration of estradiol valerate, cleavage to 17β-estradiol and valeric acid takes place during absorption by the intestinal mucosa or in the course of the first liver passage. This gives rise to estradiol and its metabolites, estrone and other metabolites. Maximum serum estradiol concentrations of 73.3 pg/mL are reached at a median of approximately 6 hours (range: 1.5–12 hours) and the area under the estradiol concentration curve [AUC(0–24hr)] was 1301 pg·hr/mL after single ingestion of a tablet containing 3 mg estradiol valerate under fasted condition on Day 1 of the 28-day sequential regimen.

Bioavailability of dienogest is about 91%. Maximum serum dienogest concentrations of 91.7 ng/mL are reached at a median of approximately 1 hour (range: 0.5–1.5 hour) and the area under the dienogest concentration curve [AUC(0–24hr)] was 964 ng/mL after single oral administration of Natazia tablet containing 2 mg estradiol valerate/3 mg dienogest under fasted condition. The pharmacokinetics of dienogest are dose-proportional within the dose range of 1–8 mg. Steady state is reached after 4 days of the same dosage of 2 mg dienogest. The mean accumulation ratio for AUC (0–24hr) is approximately 1.24.

The mean plasma pharmacokinetic parameters at steady state following repeated oral doses of a 2 mg estradiol valerate/3 mg dienogest combination tablet in fertile women under fasted condition are reported in Table 1.

Table 1: Arithmetic Mean (SD) Serum Pharmacokinetic Parameters at Steady-state (on Day 24) following Repeated Oral Doses of 2 mg EV/3 mg DNG on Days 8-24 of the 28 day Regimen in Fertile Women under Fasted Condition (N=15)

Parameter	Dienogest	Estradiol	Estrone
Cmax*	85.2 (19.7) ng/ml	70.5 (25.9) pg/ml	483 (198) pg/ml
Tmax† (hr)‡	1.5 (1–2)	3 (1.5–12)	4 (3–12)
AUC§(0–24hr)	828 (187) ng·hr/ml	1323 (480) pg·hr/ml	7562 (3403) pg·hr/ml
t½ (hr)	12.3 (1.4)	NA¶	NA

*Cmax = Maximum serum concentration†Tmax = Time to reach maximum concentration‡Median (range) for Tmax§AUC(0-24hr) = Area under the concentration-time curve from 0 hr data point up to 48 hr post-administration¶NA: Data not available
Food Effect

Concomitant food intake in women resulted in a 28% decrease for dienogest Cmax and 23% increase of estradiol Cmax while the exposure (AUC) of both dienogest and estradiol did not change.

Distribution

In serum, 38% of estradiol is bound to sex hormone-binding globulin (SHBG), 60% to albumin and 2–3% circulates in free form. An apparent volume of distribution of approximately 1.2 L/kg was determined after intravenous (IV) administration.

A relatively high fraction (10%) of circulating dienogest is present in the free form, with approximately 90% being bound non-specifically to albumin. Dienogest does not bind to SHBG and corticosteroid-binding globulin (CBG). The volume of distribution at steady state (Vd,ss) of dienogest is 46 L after the IV administration of 85 mcg 3H-dienogest.

Metabolism

After oral administration of estradiol valerate, approximately 3% of the dose is directly bioavailable as estradiol. Estradiol undergoes an extensive first-pass effect and a considerable part of the dose administered is already metabolized in the gastrointestinal mucosa. The CYP 3A family is known to play the most important role in human estradiol metabolism. Together with the pre-systemic metabolism in the liver, about 95% of the orally administered dose becomes metabolized before entering the systemic circulation. The main metabolites are estrone and its sulfate or glucuronide conjugates.

Dienogest is extensively metabolized by the known pathways of steroid metabolism (hydroxylation, conjugation), with the formation of endocrinologically mostly inactive metabolites. CYP3A4 was identified as a predominant enzyme catalyzing the metabolism of dienogest.

Excretion

Estradiol and its metabolites are mainly excreted in urine, with about 10% being excreted in the feces. The terminal half-life of estradiol is approximately 14 hours.

Dienogest is mainly excreted renally in the form of metabolites and unchanged dienogest is the dominating fraction in plasma. The terminal half-life of dienogest is approximately 11 hours.

Specific Populations

Pediatric Use: Safety and efficacy of Natazia has been established in women of reproductive age. Efficacy is expected to be the same for postpubertal adolescents under the age of 18 as for users 18 years and older. Use of this product before menarche is not indicated. [See Use in Specific Populations (8.4)]

Geriatric Use: Natazia has not been studied in postmenopausal women and is not indicated in this population. [See Use in Specific Populations (8.5).]

Renal Impairment: The pharmacokinetics of Natazia has not been studied in subjects with renal impairment. [See Use in Specific Populations (8.6).]

Hepatic Impairment: The pharmacokinetics of Natazia has not been studied in subjects with hepatic impairment.  Steroid hormones may be poorly metabolized in patients with impaired liver function. Acute or chronic disturbances of liver function may necessitate the discontinuation of COC use until markers of liver function return to normal. [See Contraindications (4), Warnings and Precautions (5.3) and Use in Specific Populations (8.7).]

Body Mass Index: The efficacy of Natazia in women with a BMI of > 30 kg/m2 has not been evaluated. [See Use in Specific Populations (8.8).]

Drug Interactions

CYP3A4 Inducers: Drugs or herbal products that induce certain enzymes, including CYP3A4, may decrease the effectiveness of COCs or increase breakthrough bleeding. Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include barbiturates, bosentan, felbamate, griseofulvin, oxcarbazepine, and topiramate. Counsel women to use an alternative method of contraception or a back-up method when moderate or weak enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer to ensure contraceptive reliability.

Dienogest is a substrate of CYP3A4. Women who take medications that are strong CYP3A4 inducers (for example, carbamazepine, phenytoin, rifampicin, and St. John’s wort) should not choose Natazia as their oral contraceptive while using these inducers and for at least 28 days after discontinuation of these inducers due to the possibility of decreased contraceptive efficacy.

The effect of the CYP3A4 inducer rifampicin was studied in an open-label, non-randomized, single center study in 16 healthy postmenopausal women. All volunteers received a treatment regimen of 2 mg estradiol valerate and 3 mg dienogest combination tablets, dosed once daily over 17 days, and of rifampicin, which was administered once daily in an oral dose of 600 mg on Days 12 to 16. 24–hr pharmacokinetics of estradiol and dienogest on Days 11 and 17 were compared. Co-administration of rifampicin with estradiol valerate/dienogest tablets led to a 52 % and 83% decrease in the mean Cmax and AUC(0–24hr), respectively, for dienogest and a 25% and 44% decrease in Cmax and AUC(0–24hr), respectively, for estradiol at steady state. [See Drug Interactions (7.1).]

Strong CYP3A4 Inhibitors: Strong CYP3A4 inhibitors such as ketoconazole increase hormone serum levels. The effect of a strong CYP3A4 inhibitor, ketoconazole, on dienogest and estradiol pharmacokinetics was studied in an open-label, two parallel-groups, one-sequence, one-way crossover study in healthy postmenopausal Caucasian women. One tablet of 2 mg estradiol valerate and 3 mg dienogest was administered orally once a day for 14 days. Twelve volunteers received an oral dose of 400 mg ketoconazole (that is, 2 tablets containing 200 mg ketoconazole) once daily for 7 days (Days 8–14). Twenty-four hour pharmacokinetics of estradiol and dienogest on Days 7 and 14 were compared. Co-administration with the strong inhibitor ketoconazole resulted in a 186% and 57% increase of AUC (0–24hr) at steady state for dienogest and estradiol. There was also a 94% and 65% increase of Cmax at steady state for dienogest and estradiol when co-administered with ketoconazole. [See Drug Interactions (7.1).]

Moderate CYP3A4 Inhibitors: Moderate CYP3A4 inhibitors such as erythromycin increase hormone serum levels. The effect of a moderate CYP3A4 inhibitor, erythromycin on dienogest and estradiol pharmacokinetics was studied in an open-label, two parallel-groups, one-sequence, one-way crossover study in healthy postmenopausal Caucasian women. One tablet of 2 mg estradiol valerate and 3 mg dienogest was administered orally once a day for 14 days. Twelve volunteers received an oral dose of 500 mg erythromycin three times a day for 7 days (Days 8–14). Twenty-four hour pharmacokinetics of estradiol and dienogest on Days 7 and 14 were compared. When co-administered with the moderate inhibitor erythromycin, the AUC (0–24hr) of dienogest and estradiol at steady state were increased by 62% and 33%, respectively. There was also a 33% and 51% increase of Cmax at steady state for dienogest and estradiol when co-administered with erythromycin. [See Drug Interactions (7.1).]

Other known CYP3A4 inhibitors such as azole antifungals, cimetidine, verapamil, macrolides, diltiazem, antidepressants, and grapefruit juice may increase plasma levels of dienogest and estradiol. [See Drug Interactions (7.1).]

HIV Protease Inhibitors: Significant changes (increase or decrease) in the plasma levels of the estrogen and progestin have been noted in some cases of co-administration of HIV protease inhibitors.

Antibiotics: There have been reports of pregnancy while taking hormonal contraceptives and antibiotics, but clinical pharmacokinetic studies have not shown consistent effects of antibiotics on plasma concentrations of synthetic steroids.

Consult the labeling of all concurrently-used drugs to obtain further information about interactions with hormonal contraceptives or the potential for enzyme alterations.

Effects of Combined Hormonal Contraceptives on Other Drugs: COCs containing ethinyl estradiol (or mestranol), may inhibit the metabolism of other compounds. COCs have been shown to significantly decrease plasma concentrations of lamotrigine, likely due to induction of lamotrigine glucuronidation. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary. Consult the labeling of the concurrently-used drug to obtain further information about interactions with COCs or the potential for enzyme alterations.

In vitro studies with human CYP enzymes did not indicate an inhibitory potential of dienogest at clinically relevant concentrations.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

In a 24 month carcinogenicity study in mice dosed orally with dienogest by gavage with doses of 5, 15 and 50 mg/kg/day (males) and 10, 30 and 100 mg/kg/day (females), the systemic exposures in the females were 1.1, 3.5, and 10.6 times the exposure (AUC of dienogest) of women taking a 3 mg dose. A statistically significantly higher incidence of stromal polyps of the uterus was observed in females given 100 mg/kg. In a similar study in rats given 1, 3, and 10 mg/kg for 104 weeks, 0.2, 1.4, and 6.1 times the exposure of women taking a 3 mg dose, there were no statistically significant drug-related neoplasms.

Dienogest was not mutagenic in in vitro reverse mutation tests in bacteria, in chromosome aberration tests in human peripheral lymphocytes, mouse lymphoma cells, and Chinese hamster lung cells, and tests of unscheduled DNA synthesis (UDS) in rat and human liver cells. Dienogest was also negative in an in vivo mouse micronucleus test, a rat liver initiation-promotion model, and an in vitro/in vivo UDS test in female rats.

13.2 Animal Toxicology and/or Pharmacology

Nonclinical studies in animals and in vitro, have shown that besides progestogenic activities, DNG is devoid of estrogenic, androgenic, glucocorticoid and mineralocorticoid activities.

14.1 Oral Contraceptive Clinical Trials

The study conducted in North America (U.S. and Canada) was a multicenter, open-label, single-arm, unintended pregnancy study. There were 490 healthy subjects between 18 and 35 years of age (mean age: 25.1 years) who were treated for up to 28 cycles of 28 days each. The racial demographic of enrolled women was: Caucasian (76%), Hispanic (13%), African-American (7%), Asian (3%), and Other (1%). The weight range for treated women was 40 to 100 kg (mean weight: 62.5 kg) and the BMI range was 14 to 30 kg/m2 (mean BMI: 23.3 kg/m2). Of treated women, 15% discontinued the study treatment due to an adverse event, 13% were lost to follow up, 10% withdrew their consent, 8% discontinued due to other reason, 1% discontinued due to protocol deviation, and 1% discontinued due to pregnancy.

The study conducted in Europe (Germany, Austria and Spain) was a multicenter, open-label, single-arm contraceptive reliability study. There were 1,377 healthy subjects between 18 and 50 years of age (mean age: 30.3 years) who were treated for 20 cycles of 28 days each. The racial demographic of enrolled women was predominantly Caucasian (99.2%). The weight range for treated women was 38 to 98 kg (mean weight: 63.8 kg) and the BMI range was 15 to 31.8 kg/m2 (mean BMI: 22.8 kg/m2). Of treated women, 10% discontinued the study treatment due to an adverse event, 5% discontinued due to other reason, 2% were lost to follow up, 2% discontinued due to protocol deviation, 2% withdrew their consent, and 1% discontinued due to pregnancy.

The Pearl Index (PI) was the primary efficacy endpoint used to assess contraceptive reliability and was assessed in each of the two studies, assuming all subjects were at risk of pregnancy in all medication cycles unless back-up contraception was documented. The PI is based on pregnancies that occurred after the onset of treatment and within 7 days after the last pill intake. Cycles in which conception did not occur, but which included the use of back-up contraception, were not included in the calculation of the PI. The PI also includes patients who did not take the drug correctly. The estimated PI for the North American study is 1.64 and the estimated PI for the European study is 1.04. The Kaplan-Meier method was also used to calculate the contraceptive failure rate.

The summary of the Pearl Indexes and cumulative contraceptive failure rates are provided in Table 2:

Table 2: Summary of the Pearl Indexes and the Cumulative Contraceptive Failure Rates

Study	Age Group	Relative Treatment Exposure Cycles*	Number of Pregnancies within 13 Cycles and 7 Days after Last Treatment	Pearl Index	Upper Limit of 95% CI	Contraceptive Failure Rate at the End of First Year
North America	18–35	3,969	5	1.64	3.82	0.016
Europe	18–35	11,275	9	1.04	1.97	0.010

*Total treatment exposure time without back-up contraception

16.1 How Supplied

Natazia (estradiol valerate and estradiol valerate/dienogest) tablets are available in 28 tablets per blister packs (NDC 54868-6183-0).

The active and inert film-coated tablets are rounded with biconvex faces, one side is embossed with a regular hexagon shape with the letters DD or DJ or DH or DN or DT.

Each blister pack (28 film-coated tablets) contains in the following order:

• 2 round biconvex dark yellow film-coated tablets with embossed “DD” in a regular hexagon on one side each containing 3 mg estradiol valerate
• 5 round biconvex medium red film-coated tablets with embossed “DJ” in a regular hexagon on one side each containing 2 mg estradiol valerate and 2 mg dienogest
• 17 round biconvex light yellow film-coated tablets with embossed “DH” in a regular hexagon on one side each containing 2 mg estradiol valerate and 3 mg dienogest
• 2 round biconvex dark red film-coated tablets with embossed “DN” in a regular hexagon on one side each containing 1 mg estradiol valerate
• 2 white round biconvex white film-coated tablets with embossed “DT” in a regular hexagon on one side (inert)

Keep out of reach of children.

16.2 Storage Conditions

Store at 25º C (77º F); excursions permitted to 15–30oC (59–86oF) [see USP Controlled Room Temperature].

17.1 Information for Patients

• Counsel patients that cigarette smoking increases the risk of serious cardiovascular events from COC use, and that women who are over 35 years old and smoke should not use COCs.
• Counsel patients that this product does not protect against HIV infection (AIDS) and other sexually transmitted diseases.
• Counsel patients on Warnings and Precautions associated with COCs.
• Counsel patients to take one tablet daily by mouth at the same time every day in the exact order noted on the blister. Instruct patients what to do in the event pills are missed. See What Should I Do if I Miss any Pills section or FDA-Approved Patient Labeling.
• Counsel women who are taking strong CYP3A4 inducers (for example, carbamazepine, phenytoin, rifampicin, and St. John’s wort) not to choose Natazia as their oral contraceptive due to the possibility of decreased contraceptive efficacy.
• Counsel patients to use a back-up or alternative method of contraception when weak or moderate enzyme inducers are used with Natazia.
• Counsel patients who are breastfeeding or who desire to breastfeed that COCs may reduce breast milk production. This is less likely to occur if breastfeeding is well established.
• Counsel any patient who starts COCs postpartum, and who has not yet had a period, to use an additional method of contraception until she has taken Natazia for 9 consecutive days.
• Counsel patients that amenorrhea may occur. Pregnancy should be ruled out in the event of amenorrhea in two or more consecutive cycles.

Relabeling of "Additional" barcode label by:

Physicians Total Care, Inc.
Tulsa, OK       74146