Amethia Lo: Indications, Dosage, Precautions, Adverse Effects
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Amethia Lo – Product Information

Manufacture: Watson Pharmaceuticals Inc. (Allergan)
Country: United States
Condition: Birth Control (Contraception), Contraception (Birth Control)
Class: Contraceptives
Form: Tablets
Ingredients: levonorgestrel, ethinyl estradiol, lactose monohydrate, microcrystalline cellulose, povidone, croscarmellose sodium, and magnesium stearate

Warning: Cigarette smoking and serious cardiovascular events

Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptives (COC) use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, COCs should not be used by women who are over 35 years of age and smoke. [See Contraindications (4).]

Indications and usage

AMETHIA Lo tablets are indicated for use by women to prevent pregnancy.

Dosage and administrations

Take one tablet by mouth at the same time every day. The dosage of AMETHIA Lo tablets is one white tablet containing levonorgestrel and ethinyl estradiol daily for 84 consecutive days, followed by one blue ethinyl estradiol tablet for 7 days. To achieve maximum contraceptive effectiveness, AMETHIA Lo tablets must be taken exactly as directed and at intervals not exceeding 24 hours.

Instruct the patient to begin taking AMETHIA Lo tablets on the first Sunday after the onset of menstruation. If menstruation begins on a Sunday, the first white tablet is taken that day. One white tablet should be taken daily for 84 consecutive days, followed by one blue tablet for 7 consecutive days. A non-hormonal back-up method of contraception (such as condoms or spermicide) should be used until a white tablet has been taken daily for 7 consecutive days. A scheduled period should occur during the 7 days that the blue tablets are taken.

Begin the next and all subsequent 91-day cycles without interruption on the same day of the week (Sunday) on which the patient began her first dose of AMETHIA Lo tablets, following the same schedule: 84 days taking a white tablet followed by 7 days taking a blue tablet. If the patient does not immediately start her next pill pack, she should protect herself from pregnancy by using a non-hormonal back-up method of contraception until she has taken a white tablet daily for 7 consecutive days.

If unscheduled spotting or bleeding occurs, instruct the patient to continue on the same regimen. If the bleeding is persistent or prolonged, advise the patient to consult her healthcare provider.

For patient instructions regarding missed pills, see PATIENT COUNSELING INFORMATION (17.2).

For postpartum women who are not breastfeeding, start AMETHIA Lo tablets no earlier than four to six weeks postpartum. If the patient starts on AMETHIA Lo tablets postpartum and has not yet had a period, evaluate for possible pregnancy, and instruct her to use an additional method of contraception until she has taken a white tablet for 7 consecutive days.

Dosage forms and strengths

AMETHIA Lo tablets are available in Extended-Cycle Tablet Dispensers, each containing a 13-week supply of tablets: 84 white tablets, each containing 0.1 mg of levonorgestrel and 0.02 mg ethinyl estradiol, and 7 blue tablets each containing 0.01 mg of ethinyl estradiol. The white tablets are round, uncoated, unscored tablets with 229 on one side and WATSON on the other side. The blue tablets are round, uncoated, unscored tablet with 230 on one side and WATSON on the other side.

Contraindications

Do not prescribe AMETHIA Lo tablets to women who are known to have the following conditions:

  • A high risk of arterial or venous thrombotic diseases. Examples include women who are known to:
  • Smoke, if over age 35
  • Have deep vein thrombosis or pulmonary embolism, now or in the past
  • Have cerebrovascular disease
  • Have coronary artery disease
  • Have thrombogenic valvular or thrombogenic rhythm diseases of the heart (for example, subacute bacterial endocarditis with valvular disease, or atrial fibrillation)
  • Have hypercoagulopathies
  • Have uncontrolled hypertension
  • Have diabetes with vascular disease
  • Have headaches with focal neurological symptoms or have migraine headaches with or without aura if over age 35
  • Breast cancer or other estrogen- or progestin-sensitive cancer, now or in the past
  • Liver tumors, benign or malignant, or liver disease
  • Pregnancy, because there is no reason to use OCs during pregnancy

Warnings and precautions

Vascular Events

Stop COCs if an arterial or deep venous thrombotic event occurs. Although 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. 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.

Use of AMETHIA Lo tablets provides women with more hormonal exposure on a yearly basis than conventional monthly oral contraceptives containing the same strength synthetic estrogens and progestins (an additional 9 and 13 weeks of exposure to progestin and estrogen, respectively, per year.)

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.

Stop COCs if there is unexplained loss of vision, proptosis, diplopia, papilledema, or retinal vascular lesions. Evaluate for retinal vein thrombosis immediately.

Carcinoma of the Breast and Cervix

Women who currently have or have had breast cancer should not use COCs because breast cancer may be hormonally sensitive.

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 are due to differences in sexual behavior and other factors.

Liver Disease

Discontinue COCs if jaundice develops. Steroid hormones may be poorly metabolized in patients with impaired liver function.

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.

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.

Gallbladder Disease

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

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 dyslipidemias. A small proportion of women will have adverse lipid changes while on COCs.

Headache

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

Bleeding Irregularities

Unscheduled (breakthrough) bleeding and spotting sometimes occur in patients on COCs, especially during the first 3 months of use. If bleeding persists, 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 product.

When prescribing AMETHIA Lo tablets, the convenience of fewer planned menses (4 per year instead of 13 per year) should be weighed against the inconvenience of increased unscheduled bleeding and/or spotting. The clinical trial that evaluated the efficacy of AMETHIA Lo tablets also assessed unscheduled bleeding. The participants in this 12-month clinical trial (N=2,185) completed the equivalent of over 20,000 28-day cycles of exposure and were composed primarily of women who had used OCs previously (89%), as opposed to new users (11%). A total of 209 subjects (9.6%) discontinued AMETHIA Lo tablets, at least in part, due to bleeding and/or spotting.

Scheduled (withdrawal) bleeding and/or spotting remained fairly constant over time, with an average of 2 to 3 days of bleeding and/or spotting per each 91-day cycle. Unscheduled bleeding and unscheduled spotting decreased over successive 91-day cycles. Table 1 below presents the number of days with unscheduled bleeding in treatment cycles 1 and 4. Table 2 presents the number of days with unscheduled spotting in treatment cycles 1 and 4.

Table 1: Total Number of Days with Unscheduled Bleeding

91-Day Treatment Cycle Days per 84-Day Interval Days per 28- Day Interval
Q1 Median Q3 Mean Mean
1st 1 4 10 6.9 1.7
4th 0 1 4 3.2 0.8

Q1=Quartile 1: 25% of women had this number of days of unscheduled bleeding

Median: 50% of women had ≤ this number of days of unscheduled bleeding

Q3=Quartile 3: 75% of women had ≤ this number of days of unscheduled bleeding

Table 2: Total Number of Days with Unscheduled Spotting

91-Day Treatment Cycle Days per 84-Day Interval Days per 28- Day Interval
Q1 Median Q3 Mean Mean
1st 1 4 11 7.4 1.9
4th 0 2 7 4.4 1.1

Q1=Quartile 1: 25% of women had ≤ this number of days of unscheduled spotting

Median: 50% of women had ≤ this number of days of unscheduled spotting

Q3=Quartile 3: 75% of women had ≤ his number of days of unscheduled spotting

Figure 1 shows the percentage of AMETHIA Lo tablets subjects participating in the primary clinical trial with ≥ 7 days or ≥ 20 days of unscheduled bleeding and/or spotting, or just unscheduled bleeding, during each 91-day treatment cycle.


Amenorrhea sometimes occurs in women who are using COCs. Pregnancy should be ruled out in the event of amenorrhea. Some women may encounter amenorrhea or oligomenorrhea after stopping COCs, especially when such a condition was pre-existent.

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.

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.

Adverse reactions

The following serious adverse reactions with the use of COCs are discussed elsewhere in the labeling:

  • Serious cardiovascular events and smoking [see BOXED WARNING]
  • Vascular events [see WARNINGS AND PRECAUTIONS (5.1)]
  • Liver disease [see WARNINGS AND PRECAUTIONS (5.3)]

Adverse reactions commonly reported by COC users are:

  • Irregular uterine bleeding
  • Nausea
  • Breast tenderness
  • Headache

Clinical Trial 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 the rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The clinical trial that evaluated the safety and efficacy of levonorgestrel/ethinyl estradiol and ethinyl estradiol was a 12-month, multicenter, non-comparative open-label study, which enrolled women aged 18 to 41, of whom 2,185 took at least one dose of levonorgestrel/ethinyl estradiol and ethinyl estradiol.

Adverse Reactions Leading to Study Discontinuation: 11% of the women discontinued from the clinical trial due to an adverse reaction; the most common adverse reactions leading to discontinuation were irregular and/or heavy uterine bleeding, headache, mood changes, nausea, acne, and weight gain.

Common Treatment-Emergent Adverse Reactions (? 5% of women): headaches (33%); irregular and/or heavy uterine bleeding (13%), dysmenorrhea (11%), nausea and/or vomiting (11%), back pain (8%).

Drug interactions

No formal drug-drug interaction studies were conducted with levonorgestrel/ethinyl estradiol and ethinyl estradiol.

Changes in Contraceptive Effectiveness Associated with Coadministration of Other Products

If a woman on hormonal contraceptives takes a drug or herbal product that induces enzymes, including CYP3A4, that metabolize contraceptive hormones, counsel her to use additional contraception or a different method of contraception. Drugs or herbal products that induce such enzymes may decrease the plasma concentrations of contraceptive hormones, and may decrease the effectiveness of hormonal contraceptives or increase breakthrough bleeding. Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include:

  • barbiturates
  • bosentan
  • carbamazepine
  • felbamate
  • griseofulvin
  • oxcarbazepine
  • phenytoin
  • rifampin
  • St. John’s wort
  • topiramate

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

Increase in Plasma Levels of Estradiol Associated with Coadministered Drugs

Coadministration of atorvastatin and certain COCs containing ethinyl estradiol increase AUC values for ethinyl estradiol by approximately 20%. Ascorbic acid and acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. CYP3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels.

Changes in Plasma Levels of Coadministered Drugs

Combination OCs containing some synthetic estrogens (e.g., ethinyl estradiol) may inhibit the metabolism of other compounds. Combination OCs 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.

Use in specific populations

Pregnancy

There is little or no increased risk of birth defects in women who inadvertently use COCs during early pregnancy. Epidemiologic studies and meta-analyses have not found an increased risk of genital or non- genital birth defects (including cardiac anomalies and limb reduction defects) following exposure to low dose COCs prior to conception or during early pregnancy.

The administration of COCs to induce withdrawal bleeding should not be used as a test for pregnancy. Combination OCs should not be used during pregnancy to treat threatened or habitual abortion.

Women who do not breastfeed may start COCs no earlier than four to six weeks postpartum.

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 estrogen and progestin from low dose COCs are present in breast milk, but these doses have not produced adverse effects in breastfeeding infants.

Pediatric Use

Safety and efficacy of AMETHIA Lo tablets have been established in women of reproductive age. Safety and efficacy are 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.

Geriatric Use

This product has not been studied in postmenopausal women and is not indicated in this population.

Overdosage

There have been no reports of serious ill effects from overdose, including ingestion by children. Overdosage may cause withdrawal bleeding in females and nausea.

Description

Levonorgestrel/ethinyl estradiol and ethinyl estradiol tablets provide an oral contraceptive regimen of 84 white tablets each containing 0.1 mg levonorgestrel and 0.02 mg ethinyl estradiol, followed by 7 blue tablets each containing 0.01 mg ethinyl estradiol.

The structural formulas for the active components are:


Levonorgestrel is chemically 18,19-Dinorpregn-4-en-20-yn-3-one, 13-ethyl-17-hydroxy-, (17α)-, (-)-.


Ethinyl Estradiol is 19-Norpregna-1,3,5(10)-trien-20-yne-3,17-diol, (17 α)-.

Inactive ingredients for the white tablets include lactose monohydrate, microcrystalline cellulose, povidone, croscarmellose sodium, and magnesium stearate.

Inactive ingredients for the blue tablets include anhydrous lactose, corn starch, stearic acid, povidone, colloidal silicon dioxide, Vitamin E and FD and C Blue # 1 aluminum lake.

Clinical pharmacology

Mechanism of Action

Combination OCs 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.

Pharmacokinetics

Absorption

No specific investigation of the absolute bioavailability of levonorgestrel/ethinyl estradiol and ethinyl estradiol in humans has been conducted. However, literature indicates that levonorgestrel is rapidly and completely absorbed after oral administration (bioavailability nearly 100%) and is not subject to first- pass metabolism. Ethinyl estradiol is rapidly and almost completely absorbed from the gastrointestinal tract but, due to first-pass metabolism in gut mucosa and liver, the systemic bioavailability of ethinyl estradiol is approximately 43%.

The mean plasma pharmacokinetic parameters of levonorgestrel/ethinyl estradiol and ethinyl estradiol following a single oral dose of three levonorgestrel/ethinyl estradiol combination tablets in normal healthy women under fasting conditions are reported in Table 3.

Table 3: Mean (SD) Pharmacokinetic Parameters Following a Single Dose Administration of Three Tablets (levonorgestrel/ethinyl estradiol combination) of Levonorgestrel/Ethinyl Estradiol and Ethinyl Estradiol in 30 Healthy Women under Fasting Conditions

AUC0 -∞ Cmax Tmax T ½
Levonorgestrel 76.5 ± 24.9 ng*hr/mL 6.0 ± 1.6 ng/mL 1.6 ± 0.6 hours 28.5 ± 8.7 hours
Ethinyl estradiol 1335.8 ± 365.3 pg*hr/mL 122.8 ± 39.5 pg/mL 1.8 ± 0.7 hours 17.5 ± 7.4 hours

AUC0-∞ = area under the drug concentration curve from time 0 to infinity

Cmax = maximum concentration

Tmax = time to maximum concentration

The effect of food on the rate and the extent of levonorgestrel and ethinyl estradiol absorption following oral administration of AMETHIA Lo tablets has not been evaluated.

Distribution

The apparent volume of distribution of levonorgestrel and ethinyl estradiol is reported to be approximately 1.8 L/kg and 4.3 L/kg, respectively. Levonorgestrel is about 97.5 to 99% protein-bound, principally to sex hormone binding globulin (SHBG) and, to a lesser extent, serum albumin. Ethinyl estradiol is about 95 to 97% bound to serum albumin. Ethinyl estradiol does not bind to SHBG, but induces SHBG synthesis, which leads to decreased levonorgestrel clearance. Following repeated daily dosing of combination levonorgestrel/ethinyl estradiol OCs, levonorgestrel plasma concentrations accumulate more than predicted based on single-dose pharmacokinetics, due in part, to increased SHBG levels that are induced by ethinyl estradiol, and a possible reduction in hepatic metabolic capacity.

Metabolism

Following absorption, levonorgestrel is conjugated at the 17β-OH position to form sulfate conjugates and, to a lesser extent, glucuronide conjugates in plasma. Significant amounts of conjugated and unconjugated 3α, 5β-tetrahydrolevonorgestrel are also present in plasma, along with much smaller amounts of 3α, 5α-tetrahydrolevonorgestrel and 16β-hydroxylevonorgestrel. Levonorgestrel and its phase I metabolites are excreted primarily as glucuronide conjugates. Metabolic clearance rates may differ among individuals by several-fold, and this may account in part for the wide variation observed in levonorgestrel concentrations among users.

First-pass metabolism of ethinyl estradiol involves formation of ethinyl estradiol-3-sulfate in the gut wall, followed by 2-hydroxylation of a portion of the remaining untransformed ethinyl estradiol by hepatic cytochrome P450 3A4 (CYP3A4). Levels of CYP3A4 vary widely among individuals and can explain the variation in rates of ethinyl estradiol hydroxylation. Hydroxylation at the 4-, 6-, and 16- positions may also occur, although to a much lesser extent than 2-hydroxylation. The various hydroxylated metabolites are subject to further methylation and/or conjugation.

Excretion

About 45% of levonorgestrel and its metabolites are excreted in the urine and about 32% are excreted in feces, mostly as glucuronide conjugates. Ethinyl estradiol is excreted in the urine and feces as glucuronide and sulfate conjugates, and then undergoes enterohepatic recirculation.

Race

The effect of race on the pharmacokinetics of levonorgestrel/ethinyl estradiol and ethinyl estradiol has not been evaluated.

Renal and Hepatic Impairment

No formal studies were conducted to evaluate the effect of hepatic or renal disease on the disposition of levonorgestrel/ethinyl estradiol and ethinyl estradiol. However, steroid hormones may be poorly metabolized in patients with impaired liver function.

Nonclinical toxicology

Carcinogenesis, Mutagenesis, Impairment of Fertility

[See WARNINGS AND PRECAUTIONS (5.2, 5.3).]

Clinical studies

In a 12-month multicenter open-label clinical trial, 2,185 women aged 18 to 41 were studied to assess the safety and efficacy of levonorgestrel/ethinyl estradiol and ethinyl estradiol, completing the equivalent of 20,937 28-day cycles of exposure. The racial demographic of those enrolled was: Caucasian (75%), African-American (12%), Hispanic (10%), Asian (2%), and Other (2%). There were no exclusions for body mass index (BMI) or weight. The weight range for those women treated was 87 to 381 lbs., with a mean weight of 159 lbs. Among the women in the trial, 59% were current or recent hormonal contraceptive users, 30% were prior users (had used hormonal contraceptives in the past but not in the 6 months prior to enrollment) and 11% were new starts. Of treated women, 14.2% were lost to follow-up, 11.6% discontinued due to an adverse event, and 10.3% discontinued by withdrawing their consent.

The pregnancy rate (Pearl Index [PI]) in women aged 18 to 35 years was 2.74 pregnancies per 100 women-years of use (95% confidence interval 1.92 to 3.78), based on 36 pregnancies that occurred after the onset of treatment and within 14 days after the last combination pill. Cycles in which conception did not occur, but which included the use of backup contraception, were not included in the calculation of the PI. The PI includes patients who did not take the drug correctly.

How supplied/storage and handling

AMETHIA Lo tablets are available in an Extended-Cycle Tablet Dispenser that contains 84 round, white tablets and 7 round, blue tablets. Each white tablet (229 on one side and WATSON on the other side) contains 0.1 mg levonorgestrel and 0.02 mg ethinyl estradiol. Each blue tablet (230 on one side and WATSON on the other side) contains 0.01 mg ethinyl estradiol. The tablets should not be removed from the protective blister packaging and outer plastic dispenser to avoid damage to the product.

The plastic dispenser should be kept in the foil pouch until dispensed to the patient. Box of 2 Extended-Cycle Tablet Dispensers NDC 52544-228-29

Storage

Store at 20° to 25° C (68° to77° F) [See USP Controlled Room Temperature].

Patient counseling information

See FDA-APPROVED PATIENT LABELING (17.2)

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 to take one tablet daily by mouth at the same time every day. Instruct patients what to do in the event pills are missed.
  • Counsel patients to use a back-up or alternative method of contraception when enzyme inducers are used with COCs.
  • 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 a white tablet for 7 consecutive days.