Levonorgestrel and Ethinyl Estradol Tablets

Name: Levonorgestrel and Ethinyl Estradol Tablets

Indications

LYBREL (levonorgestrel and ethinyl estradol tablets) is indicated for the prevention of pregnancy in women who elect to use oral contraceptives as a method of contraception.

Oral contraceptives are highly effective for pregnancy prevention. Table 2 lists the typical unintended pregnancy rates for users of combination oral contraceptives and other methods of contraception. The efficacy of these contraceptive methods, except sterilization, the IUD, and implants, depend upon the reliability with which they are used. Correct and consistent use of methods can result in lower failure rates.

Table 2: Percentage of Women Experiencing an Unintended Pregnancy During The First Year of Typical Use and The First Year of Perfect Use of Contraception and The Percentage Continuing Use at The End of the First Year. United States.

  % of Women Experiencing an Unintended Pregnancy within the First Year of Use % of Women Continuing Use at One Year 3
Method (1) Typical Use 1 (2) Perfect Use 2 (3) (4)
Chance 4 85 85  
Spermicides 5 26 6 40
Periodic abstinence 25   63
  Calendar   9  
  Ovulation Method   3  
  Sympto-Thermal 6   2  
  Post-Ovulation   1  
Cap 7      
  Parous Women 40 26 42
  Nulliparous Women 20 9 56
Sponge      
  Parous Women 40 20 42
  Nulliparous Women 20 9 56
Diaphragm 7 20 6 56
Withdrawal 19 4  
Condom 8      
  Female (Reality™) 21 5 56
  Male 14 3 61
Pill 5   71
  Progestin only   0.5  
  Combined   0.1  
IUD      
  Progesterone T 2.0 1.5 81
  Copper T380A 0.8 0.6 78
  LNg 20 0.1 0.1 81
Depo-Provera® 0.3 0.3 70
Levonorgestrel      
Implants (Norplant®) 0.05 0.05 88
Female Sterilization 0.5 0.5 100
Male Sterilization 0.15 0.10 100
Emergency Contraceptive Pills: The FDA has concluded that certain combined oral contraceptives containing ethinyl estradiol and norgestrel or levonorgestrel are safe and effective for use as postcoital emergency contraception. Treatment initiated within 72 hours after unprotected intercourse reduces the risk of pregnancy by atleast 75%.9
Lactation Amenorrhea Method: LAM is a highly effective, temporary method of contraception.10
Source: Trussell J. Contraceptive efficacy. In: Hatcher RA, Trussell J, Stewart F, Cates W, Stewart GK, Kowel D, Guest F. Contraceptive Technology: Seventeenth Revised Edition. New York NY: Irvington Publishers; 1998.
1. Among typical couples who initiate use of a method (not necessarily for the first time), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any other reason.
2. Among couples who initiate use of a method (not necessarily for the first time) and who use it perfectly (both consistently and correctly), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any other reason.
3. Among couples attempting to avoid pregnancy, the percentage who continue to use a method for one year.
4. The percents becoming pregnant in columns (2) and (3) are based on data from populations where contraception is not used and from women who cease using contraception in order to become pregnant. Among such populations, about 89% become pregnant within one year. This estimate was lowered slightly (to 85%) to represent the percent who would become pregnant within one year among women now relying on reversible methods of contraception if they abandoned contraception altogether.
5. Foams, creams, gels, vaginal suppositories, and vaginal film.
6. Cervical mucus (ovulation) method supplemented by calendar in the pre-ovulatory and basal body temperature in the post-ovulatory phases.
7. With spermicidal cream or jelly.
8. Without spermicides.
9. The treatment schedule is one dose within 72 hours after unprotected intercourse, and a second dose 12 hours after the first dose. The FDA has declared the following dosage regimens of oral contraceptives to be safe and effective for emergency contraception: for tablets containing 50 mcg of ethinyl estradiol and 500 mcg of norgestrel 1 dose is 2 tablets; for tablets containing 20 mcg of ethinyl estradiol and 100 mcg of levonorgestrel 1 dose is 5 tablets; for tablets containing 30 mcg of ethinyl estradiol and 150 mcg of levonorgestrel 1 dose is 4 tablets.
10. However, to maintain effective protection against pregnancy, another method of contraception must be used as soon as menstruation resumes, the frequency or duration of breastfeeds is reduced, bottle feeds are introduced, or the baby reaches 6 months of age.

Side effects

An increased risk of the following serious adverse reactions (see WARNINGS section for additional information) has been associated with the use of oral contraceptives:

Thromboembolic and thrombotic disorders and other vascular problems (including thrombophlebitis and venous thrombosis with or without pulmonary embolism, mesenteric thrombosis, arterial thromboembolism, myocardial infarction, cerebral hemorrhage, cerebral thrombosis, transient ischemic attack), carcinoma of the reproductive organs and breasts, hepatic neoplasia/liver disease (including hepatic adenomas or benign liver tumors), ocular lesions (including retinal vascular thrombosis), gallbladder disease, carbohydrate and lipid effects, elevated blood pressure, and headache including migraine.

The following adverse reactions have been reported in patients receiving oral contraceptives and are believed to be drug related (alphabetically listed):

Acne
Amenorrhea
Anaphylactic/anaphylactoid reactions, including urticaria, angioedema, and severe reactions with respiratory and circulatory symptoms
Breast changes: tenderness, pain, enlargement, secretion
Budd-Chiari syndrome
Cervical erosion and secretion, change in
Cholestatic jaundice
Chorea, exacerbation of
Colitis
Contact lenses, intolerance to
Corneal curvature (steepening), change in
Dizziness
Edema/fluid retention
Erythema multiforme
Erythema nodosum
Focal nodular hyperplasia
Gastrointestinal symptoms (such as abdominal pain, cramps, and bloating)
Hirsutism
Infertility after discontinuation of treatment, temporary
Lactation, diminution in, when given immediately postpartum
Libido, change in
Melasma/chloasma which may persist
Menstrual flow, change in
Mood changes, including depression
Nausea
Nervousness
Pancreatitis
Porphyria, exacerbation of
Rash (allergic)
Scalp hair, loss of
Serum folate levels, decrease in
Spotting
Systemic lupus erythematosus, exacerbation of
Unscheduled bleeding
Vaginitis, including candidiasis
Varicose veins, aggravation of
Vomiting
Weight or appetite (increase or decrease), change in

The following adverse reactions have been reported in users of oral contraceptives

Cataracts
Cystitis-like syndrome
Dysmenorrhea
Hemolytic uremic syndrome
Hemorrhagic eruption
Optic neuritis, which may lead to partial or complete loss of vision
Premenstrual syndrome
Renal function, impaired

Overdose

Symptoms of oral contraceptive overdosage in adults and children may include nausea, vomiting, breast tenderness, dizziness, abdominal pain, drowsiness/fatigue; withdrawal bleeding may occur in females. There is no specific antidote and further treatment of overdose, if necessary, is directed to the symptoms.

Noncontraceptive Health Benefits

The following noncontraceptive health benefits related to the use of oral contraceptives are supported by epidemiological studies which largely utilized oral contraceptive formulations containing doses exceeding 0.035 mg of ethinyl estradiol or 0.05 mg of mestranol.

Effects on menses

May decrease blood loss and may decrease the incidence of iron-deficiency anemia

May decrease incidence of dysmenorrhea

Effects related to inhibition of ovulation

May decrease incidence of functional ovarian cysts

May decrease incidence of ectopic pregnancies

Effects from long-term use

May decrease incidence of fibroadenomas and fibrocystic disease of the breast

May decrease incidence of acute pelvic inflammatory disease

May decrease incidence of endometrial cancer

May decrease incidence of ovarian cancer

Clinical pharmacology

Mode of Action

Combination oral contraceptives act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increase the difficulty of sperm entry into the uterus) and the endometrium (which reduce the likelihood of implantation).

Pharmacokinetics

Absorption

No specific investigation of the absolute bioavailability of LYBREL (levonorgestrel and ethinyl estradol tablets) in humans has been conducted. However, literature indicates that levonorgestrel is rapidly and completely absorbed after oral administration (bioavailability about 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 bioavailability of ethinyl estradiol is between 38% and 48%.

A summary of the single dose and multiple dose levonorgestrel and ethinyl estradiol pharmacokinetic parameters for 18 women under fasting conditions is provided in Table 1. The plasma concentrations of levonorgestrel and ethinyl estradiol reached steady-state by approximately day 14. Levonorgestrel and ethinyl estradiol concentrations did not increase from days 14 to 28, but did increase from days 1 to 28.

Table 1: Mean (SD) Pharmacokinetic Parameters of LYBREL (levonorgestrel and ethinyl estradol tablets) Over a 28-Day Dosing Period

  LNG
Day Cmax(ng/mL) Tmax(h) t½(h) AUC0-24(ng•h/mL)
1 2.4 (0.9) 1.2 (0.4) - 16 (8)
14 5.4 (2.1) 1.7 (1.4) - 68 (36)
28 5.7 (2.1) 1.3 (0.8) 36 (19) 74 (41)
  EE
Day (pg/mL) (h) (h) (pg•h/mL)
1 47.7 (20.1) 1.3 (0.5) - 378 (140)
14 72.7 (37.2) 1.4 (0.5) - 695 (361)
28 74.4 (29.7) 1.4 (0.5) 21 (7) 717 (351)

The mean plasma concentrations of levonorgestrel and ethinyl estradiol following single (day 1) and multiple (days 14 and 28) oral administrations of levonorgestrel 90 mcg in combination with ethinyl estradiol 20 mcg to 18 healthy women is provided in Figure 1.

Figure 1: Mean Plasma ± SD† Concentrations of Levonorgestrel and Ethinyl Estradiol Following Single (Day 1) and Multiple (Days 14 and 28) Oral Administrations of Levonorgestrel 90 mcg in Combination with Ethinyl Estradiol 20 mcg to Healthy Women

The effect of food on the rate and the extent of levonorgestrel and ethinyl estradiol absorption following oral administration of LYBREL (levonorgestrel and ethinyl estradol tablets) has not been evaluated.

Distribution

Levonorgestrel in serum is primarily bound to sex hormone-binding globulin (SHBG). Ethinyl estradiol is about 97% bound to serum albumin. Ethinyl estradiol does not bind to SHBG, but induces SHBG synthesis.

Metabolism

Levonorgestrel: The most important metabolic pathways are reduction of the Δ4-3-oxo group and hydroxylation at positions 2α, 1β, followed by conjugation. Most of the circulating metabolites are sulfates of 3α, 5β-tetrahydro-levonorgestrel, while excretion occurs predominantly in the form of glucuronides. Some of the parent levonorgestrel also circulates as 17β-sulfate. 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.

Ethinyl estradiol: Cytochrome P450 enzymes (CYP3A4) in the liver are responsible for the 2-hydroxylation that is the major oxidative reaction. The 2-hydroxy metabolite is further transformed by methylation, sulfation, and glucuronidation prior to urinary and fecal excretion. Levels of CYP3A4 vary widely among individuals and can explain the variation in rates of ethinyl estradiol 2-hydroxylation.

Excretion

The terminal elimination half-life for levonorgestrel in LYBREL (levonorgestrel and ethinyl estradol tablets) is about 36 hours. Levonorgestrel and its metabolites are excreted in the urine (40% to 68%) and in feces (16% to 48%). The terminal elimination half-life of ethinyl estradiol in LYBREL (levonorgestrel and ethinyl estradol tablets) is about 21 hours.

Ethinyl estradiol is excreted in the urine and feces as glucuronide and sulfate conjugates and undergoes enterohepatic recirculation.

Special Populations

Race

No formal studies on the effect of race on the pharmacokinetic parameters of LYBREL (levonorgestrel and ethinyl estradol tablets) were conducted.

Hepatic Insufficiency

No formal studies have evaluated the effect of hepatic disease on the disposition of LYBREL (levonorgestrel and ethinyl estradol tablets) . However, steroid hormones may be poorly metabolized in patients with impaired liver function.

Renal Insufficiency

No formal studies have evaluated the effect of renal disease on the disposition of LYBREL (levonorgestrel and ethinyl estradol tablets) .

Drug-Drug Interactions

See PRECAUTIONS section - DRUG INTERACTIONS.

Clinical Studies

The efficacy and safety of LYBREL (levonorgestrel and ethinyl estradol tablets) were studied in 2 one-year clinical trials of subjects age 18­49. There were no exclusions for body mass index (BMI), weight, or bleeding history.

The primary efficacy and safety study (313-NA) was a one-year open-label clinical trial that treated 2,134 subjects in North America. Of these subjects 1,213 (56.8%) discontinued prematurely, including 102 (4.8%) discontinued by the Sponsor for early study closure. The mean weight of subjects in this study was 70.38 kg. The efficacy of LYBREL (levonorgestrel and ethinyl estradol tablets) was assessed by the number of pregnancies that occurred after the onset of treatment and within 14 days of the last dose. Among subjects 35 years or less, there were 23 pregnancies (4 of these occurred during the interval 1 to 14 days after the last day of pill use) during 12,572 28-day pill packs of use. The resulting total Pearl Index was 2.38 (95% CI: 1.51, 3.57) and the one-year life table pregnancy rate was 2.39 (95% CI: 1.57, 3.62). Pill pack cycles during which subjects used back-up contraception or were not sexually active were not included in these calculations. Among women 35 years or less who took the pills completely as directed, there were 15 pregnancies (method failures) resulting in a Pearl Index of 1.55 (95% CI: 0.87, 2.56) and the one-year life table pregnancy rate was 1.59 (95% CI: 0.95-2.67).

In a second supportive study conducted in Europe (315-EU), 641 subjects were randomized to LYBREL (levonorgestrel and ethinyl estradol tablets) (n=323) or the cyclic comparator of 100 mcg levonorgestrel and 20 mcg ethinyl estradiol (n=318). The mean weight of subjects in this study was 63.86 kg. The efficacy analysis among women 35 years or less included 2,756 LYBREL (levonorgestrel and ethinyl estradol tablets) pill packs and 2,886 cyclic comparator pill packs. There was one pregnancy in the LYBREL (levonorgestrel and ethinyl estradol tablets) group that occurred within 14 days following the last dose. There were three pregnancies in the cyclic comparator group.

Inhibition of Menses (Bleeding Profile)

The bleeding profile for subjects in Study 313-NA also was assessed. Women with a history of unscheduled bleeding and/or spotting were not excluded from the study.

In those subjects who provided complete bleeding data, the percentage of patients who were amenorrheic in a given cycle and remained amenorrheic through cycle 13 (cumulative amenorrhea rate) was determined (Figure 2).

Figure 2: Percentage of Subjects with Cumulative Amenorrhea for Each Pill Pack through Pill Pack 13

When prescribing LYBREL (levonorgestrel and ethinyl estradol tablets) , the convenience of having no scheduled menstrual bleeding should be weighed against the inconvenience of unscheduled bleeding and spotting (see WARNINGS).

What should i avoid while taking ethinyl estradiol and levonorgestrel?

Smoking can increase your risk of blood clots, stroke, or heart attack caused by birth control pills, especially if you are older than 35.

This medication will not protect you from sexually transmitted diseases--including HIV and AIDS. Using a condom is the only way to protect yourself from these diseases.

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