Ethinyl Estradiol and Norgestrel
Pronunciation
(ETH in il es tra DYE ole & nor JES trel)
U.S. Brand Names
Cryselle™; Lo/Ovral®; Low-Ogestrel®; Ogestrel®; Ovral® [DSC]
Synonyms
Morning After Pill; Norgestrel and Ethinyl Estradiol
Generic Available
Yes
Canadian Brand Names
Ovral®
Use
Prevention of pregnancy; postcoital contraceptive or "morning after" pill
Use - Unlabeled/Investigational
Treatment of hypermenorrhea (menorrhagia); pain associated with endometriosis; dysmenorrhea; dysfunctional uterine bleeding
Pregnancy Risk Factor
X
Pregnancy Implications
Pregnancy should be ruled out prior to treatment and discontinued if pregnancy occurs. In general, the use of combination hormonal contraceptives when inadvertently taken early in pregnancy have not been associated with teratogenic effects. Due to increased risk of thromboembolism postpartum, combination hormonal contraceptives should not be started earlier than 4-6 weeks following delivery. Hormonal contraceptives may be less effective in obese patients. An increase in oral contraceptive failure was noted in women with a BMI >27.3. Similar findings were noted in patients weighing
90 kg (198 lb) using the contraceptive patch.
Lactation
Enters breast milk/not recommended (AAP rates "compatible")
Contraindications
Hypersensitivity to ethinyl estradiol, norgestrel, or any component of the formulation; history of or current thrombophlebitis or venous thromboembolic disorders (including DVT, PE); active or recent (within 1 year) arterial thromboembolic disease (eg, stroke, MI); cerebral vascular disease, coronary artery disease, valvular heart disease with complications, severe hypertension; diabetes mellitus with vascular involvement; severe headache with focal neurological symptoms; known or suspected breast carcinoma, endometrial cancer, estrogen-dependent neoplasms, undiagnosed abnormal genital bleeding; hepatic dysfunction or tumor, cholestatic jaundice of pregnancy, jaundice with prior combination hormonal contraceptive use; major surgery with prolonged immobilization; heavy smoking (
15 cigarettes/day) in patients >35 years of age; pregnancy
Warnings/Precautions
Combination hormonal contraceptives do not protect against HIV infection or other sexually-transmitted diseases. The risk of cardiovascular side effects increases in women who smoke cigarettes, especially those who are >35 years of age; women who use combination hormonal contraceptives should be strongly advised not to smoke. Combination hormonal contraceptives may lead to increased risk of myocardial infarction, use with caution in patients with risk factors for coronary artery disease. May increase the risk of thromboembolism. Combination hormonal contraceptives may have a dose-related risk of vascular disease, hypertension, and gallbladder disease. Women with hypertension should be encouraged to use another form of contraception. The use of combination hormonal contraceptives has been associated with a slight increase in frequency of breast cancer, however, studies are not consistent. Combination hormonal contraceptives may cause glucose intolerance. Retinal thrombosis has been reported (rarely). Use with caution in patients with renal disease, conditions that may be aggravated by fluid retention, depression, or history of migraine. Not for use prior to menarche.
The minimum dosage combination of estrogen/progestin that will effectively treat the individual patient should be used. New patients should be started on products containing <50 mcg of estrogen per tablet.
Adverse Reactions
Frequency not defined.
Cardiovascular: Arterial thromboembolism, cerebral hemorrhage, cerebral thrombosis, edema, hypertension, mesenteric thrombosis, MI
Central nervous system: Depression, dizziness, headache, migraine, nervousness, premenstrual syndrome, stroke
Dermatologic: Acne, erythema multiforme, erythema nodosum, hirsutism, loss of scalp hair, melasma (may persist), rash (allergic)
Endocrine & metabolic: Amenorrhea, breakthrough bleeding, breast enlargement, breast secretion, breast tenderness, carbohydrate intolerance, lactation decreased (postpartum), glucose tolerance decreased, libido changes, menstrual flow changes, sex hormone-binding globulins (SHBG) increased, spotting, temporary infertility (following discontinuation), thyroid-binding globulin increased, triglycerides increased
Gastrointestinal: Abdominal cramps, appetite changes, bloating, cholestasis, colitis, gallbladder disease, jaundice, nausea, vomiting, weight gain/loss
Genitourinary: Cervical erosion changes, cervical secretion changes, cystitis-like syndrome, vaginal candidiasis, vaginitis
Hematologic: Antithrombin III decreased, folate levels decreased, hemolytic uremic syndrome, norepinephrine induced platelet aggregability increased, porphyria, prothrombin increased; factors VII, VIII, IX, and X increased
Hepatic: Benign liver tumors, Budd-Chiari syndrome, cholestatic jaundice, hepatic adenomas
Local: Thrombophlebitis
Ocular: Cataracts, change in corneal curvature (steepening), contact lens intolerance, optic neuritis, retinal thrombosis
Renal: Impaired renal function
Respiratory: Pulmonary thromboembolism
Miscellaneous: Hemorrhagic eruption
Overdosage/Toxicology
Toxicity is unlikely following single exposures of excessive doses. May cause withdrawal bleeding in females. Any treatment following emesis and charcoal administration should be supportive and symptomatic.
Drug Interactions
Ethinyl estradiol: Substrate of CYP2C8/9 (minor), 3A4 (major), 3A5-7 (minor); Inhibits CYP1A2 (weak), 2B6 (weak), 2C19 (weak), 3A4 (weak)
Norgestrel: Substrate of CYP3A4 (major)
Acetaminophen: May increase plasma concentration of synthetic estrogens, possibly by inhibiting conjugation. Combination hormonal contraceptives may also decrease the plasma concentration of acetaminophen.
Acitretin: Interferes with the contraceptive effect of microdosed progestin-containing "minipill" preparations. The effect on other progestational contraceptives (eg, implants, injectables) is unknown.
Aminoglutethimide: May increase CYP metabolism of progestins leading to possible decrease in contraceptive effectiveness. Use of a nonhormonal contraceptive product is recommended.
Antibiotics (ampicillin, tetracycline): Pregnancy has been reported following concomitant use, however, pharmacokinetic studies have not shown consistent effects with these antibiotics on plasma concentrations of synthetic steroids. Use of a nonhormonal contraceptive product is recommended.
Anticoagulants: Combination hormonal contraceptives may increase or decrease the effects of coumarin derivatives. Combination hormonal contraceptives may also increase risk of thromboembolic disorders
Anticonvulsants (carbamazepine, felbamate, phenobarbital, phenytoin, topiramate): Increase the metabolism of ethinyl estradiol and/or some progestins, leading to possible decrease in contraceptive effectiveness. Use of a nonhormonal contraceptive product is recommended.
Ascorbic acid: Doses of ascorbic acid (vitamin C) 1 g/day have been reported to increase plasma concentration of synthetic estrogens by ~47%, possibly by inhibiting conjugation; clinical implications are unclear.
Atorvastatin: Atorvastatin increases the AUC for norethindrone and ethinyl estradiol.
Benzodiazepines: Combination hormonal contraceptives may decrease the clearance of some benzodiazepines (alprazolam, chlordiazepoxide, diazepam) and increase the clearance of others (lorazepam, oxazepam, temazepam)
Clofibric acid: Combination hormonal contraceptives may increase the clearance of clofibric acid.
Cyclosporine: Combination hormonal contraceptives may inhibit the metabolism of cyclosporine, leading to increased plasma concentrations; monitor cyclosporine.
CYP3A4 inducers: CYP3A4 inducers may decrease the levels/effects of estrogens and norgestrel. Example inducers include aminoglutethimide, carbamazepine, nafcillin, nevirapine, phenobarbital, phenytoin, and rifamycins.
Griseofulvin: Griseofulvin may induce the metabolism of combination hormonal contraceptives causing menstrual changes; pregnancies have been reported. Use of barrier form of contraception is suggested while on griseofulvin therapy.
Morphine: Combination hormonal contraceptives may increase the clearance of morphine.
Non-nucleoside reverse transcriptase inhibitors (NNRTIs): Nevirapine may decrease plasma levels of combination hormonal contraceptives; use of a nonhormonal contraceptive product is recommended. No data for delavirdine; incomplete data for efavirenz.
Prednisolone: Ethinyl estradiol may inhibit the metabolism of prednisolone, leading to increased plasma concentrations.
Protease inhibitors: Amprenavir, lopinavir, nelfinavir, and ritonavir have been shown to decrease plasma levels of combination hormonal contraceptives; use of a nonhormonal contraceptive product is recommended. Indinavir has been shown to increase plasma levels of combination hormonal contraceptives. No data for saquinavir.
Rifampin: Rifampin increases the metabolism of ethinyl estradiol and some progestins (norethindrone) resulting in decreased contraceptive effectiveness and increased menstrual irregularities. Use of a nonhormonal contraceptive product is recommended.
Salicylic acid: Combination hormonal contraceptives may increase the clearance of salicylic acid.
Selegiline: Combination hormonal contraceptives may increase the serum concentration of selegiline.
Theophylline: Ethinyl estradiol may inhibit the metabolism of theophylline, leading to increased plasma concentrations.
Tricyclic antidepressants (amitriptyline, imipramine, nortriptyline): Metabolism may be inhibited by combination hormonal contraceptives, increasing plasma levels of antidepressant; use caution.
Ethanol/Nutrition/Herb Interactions
Food: CNS effects of caffeine may be enhanced if combination hormonal contraceptives are used concurrently with caffeine. Grapefruit juice increases ethinyl estradiol concentrations and would be expected to increase progesterone serum levels as well; clinical implications are unclear.
Herb/Nutraceutical: St John's wort may decrease the effectiveness of combination hormonal contraceptives by inducing hepatic enzymes. Avoid dong quai and black cohosh (have estrogen activity). Avoid saw palmetto, red clover, ginseng.
Stability
Store at controlled room temperature of 25°C (77°F).
Mechanism of Action
Combination hormonal contraceptives inhibit ovulation via a negative feedback mechanism on the hypothalamus, which alters the normal pattern of gonadotropin secretion of a follicle-stimulating hormone (FSH) and luteinizing hormone by the anterior pituitary. The follicular phase FSH and midcycle surge of gonadotropins are inhibited. In addition, combination hormonal contraceptives produce alterations in the genital tract, including changes in the cervical mucus, rendering it unfavorable for sperm penetration even if ovulation occurs. Changes in the endometrium may also occur, producing an unfavorable environment for nidation. Combination hormonal contraceptive drugs may alter the tubal transport of the ova through the fallopian tubes. Progestational agents may also alter sperm fertility.
Pharmacodynamics/Kinetics
See individual agents.
Dosage
Oral: Adults: Female:
Contraception:
Schedule 1 (Sunday starter): Dose begins on first Sunday after onset of menstruation; if the menstrual period starts on Sunday, take first tablet that very same day. With a Sunday start, an additional method of contraception should be used until after the first 7 days of consecutive administration.
For 21-tablet package: Dosage is 1 tablet daily for 21 consecutive days, followed by 7 days off of the medication; a new course begins on the 8th day after the last tablet is taken.
For 28-tablet package: Dosage is 1 tablet daily without interruption.
Schedule 2 (Day 1 starter): Dose starts on first day of menstrual cycle taking 1 tablet daily.
For 21-tablet package: Dosage is 1 tablet daily for 21 consecutive days, followed by 7 days off of the medication; a new course begins on the 8th day after the last tablet is taken.
For 28-tablet package: Dosage is 1 tablet daily without interruption.
If all doses have been taken on schedule and one menstrual period is missed, continue dosing cycle. If two consecutive menstrual periods are missed, pregnancy test is required before new dosing cycle is started.
Missed doses monophasic formulations (refer to package insert for complete information):
One dose missed: Take as soon as remembered or take 2 tablets next day
Two consecutive doses missed in the first 2 weeks: Take 2 tablets as soon as remembered or 2 tablets next 2 days. An additional method of contraception should be used for 7 days after missed dose.
Two consecutive doses missed in week 3 or three consecutive doses missed at any time:
Schedule 1 (Sunday starter): Continue to take 1 tablet daily until Sunday, then discard the rest of the pack, and a new pack is started that same day.
Schedule 2 (Day 1 starter): Current pack should be discarded, and a new pack started that same day. An additional method of contraception should be used for 7 days after missed dose.
Postcoital contraception:
Ethinyl estradiol 0.03 mg and norgestrel 0.3 mg formulation: 4 tablets within 72 hours of unprotected intercourse and 4 tablets 12 hours after first dose
Ethinyl estradiol 0.05 mg and norgestrel 0.5 mg formulation: 2 tablets within 72 hours of unprotected intercourse and 2 tablets 12 hours after first dose
Dosage adjustment in renal impairment: Specific guidelines not available; use with caution.
Dosage adjustment in hepatic impairment: Contraindicated in patients with hepatic impairment.
Administration
Administer at the same time each day.
Monitoring Parameters
Blood pressure, breast exam, Pap smear, and pregnancy; lipid profiles in patients being treated for hyperlipidemias
Dietary Considerations
Should be taken at same time each day.
Patient Education
Oral contraceptives do not protect against HIV or other sexually-transmitted diseases. Take exactly as directed by prescriber (also see package insert). You are at risk of becoming pregnant if doses are missed. Detailed and complete information on dosing and missed doses can be found in the package insert. Be aware that some medications may reduce the effectiveness of oral contraceptives; an alternate form of contraception may be needed. Check all medicines (prescription and OTC), herbal, and alternative products with prescriber. It is important that you check your blood pressure monthly (on same day each month) and that you have an annual physical assessment, Pap smear, and vision assessment while taking this medication. Avoid smoking while taking this medication; smoking increases risk of adverse effects, including thromboembolic events and heart attacks. You may experience loss of appetite (small, frequent meals will help); or constipation (increased exercise, fluids, fruit, fiber, or stool softeners may help). If you have diabetes, use accurate serum glucose testing to identify any changes in glucose tolerance; notify prescriber of significant changes so antidiabetic medication can be adjusted if necessary. Report immediately pain or muscle soreness; warmth, swelling, pain, or redness in calves; shortness of breath; sudden loss of vision; unresolved leg/ foot swelling; change in menstrual pattern (unusual bleeding, amenorrhea, breakthrough spotting); breast tenderness that does not go away; acute abdominal cramping; signs of vaginal infection (drainage, pain, itching); CNS changes (blurred vision, confusion, acute anxiety, or unresolved depression); or significant weight gain (>5 lb/week). Notify prescriber of changes in contact lens tolerance.
Pregnancy/breast-feeding precautions: This medication should not be used during pregnancy. If you suspect you may become pregnant, contact prescriber immediately. Breast-feeding is not recommended.
Emergency contraception: Not recommended for ongoing pregnancy protection or as a routine form of contraception. Contact prescriber if vomiting occurs within 1 hour of taking dose.
Cardiovascular Considerations
It is important to recognize that oral contraceptives may induce or worsen hypertension. These problems are less severe with low-dose oral contraceptives. Furthermore, oral contraceptives may precipitate thromboembolic events, particularly in women who smoke. It is important that patients on long-term oral contraceptives undergo monitoring of blood pressure and avoid cigarette use.
Dental Health: Effects on Dental Treatment
When prescribing antibiotics, patient must be warned to use additional methods of birth control if on oral contraceptives.
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
May cause depression, migraine, dizziness, anxiety, headache, and stroke
Mental Health: Effects on Psychiatric Treatment
Barbiturates decrease the effects of oral contraceptives; may increase the toxicity of the benzodiazepines and TCAs. Associated with an increased risk of developing dementia in postmenopausal women
65 years of age when treated with conjugated estrogen and medroxyprogesterone acetate.
Dosage Forms
[DSC] = Discontinued product
Tablet, monophasic formulations:
Cryselle™: Ethinyl estradiol 0.03 mg and norgestrel 0.3 mg [21 white tablets and 7 light green inactive tablets] (28s)
Low-Ogestrel® 28: Ethinyl estradiol 0.03 mg and norgestrel 0.3 mg [21 white tablets and 7 peach inactive tablets] (28s)
Lo/Ovral® 28: Ethinyl estradiol 0.03 mg and norgestrel 0.3 mg [21 white tablets and 7 pink inactive tablets] (28s)
Ovral® 21: Ethinyl estradiol 0.05 mg and norgestrel 0.5 mg [white tablets] (21s) [DSC]
Ogestrel® 28: Ethinyl estradiol 0.05 mg and norgestrel 0.5 mg [21 white tablets and 7 peach inactive tablets] (28s)
Ovral® 28: Ethinyl estradiol 0.05 mg and norgestrel 0.5 mg [21 white tablets and 7 pink inactive tablets] (28s) [DSC]
References
"American Academy of Pediatrics Committee on Drugs. The Transfer of Drugs and Other Chemicals Into Human Milk,"Pediatrics, 2001, 108(3):776-89.
Burkman R, Schlesselman JJ, and Zieman M, "Safety Concerns and Health Benefits Associated With Oral Contraception,"Am J Obstet Gynecol, 2004, 190(4 Suppl):5-22.
"Guidelines for the Use of Antiretroviral Agents in HIV-infected Adults and Adolescents. Panel on Clinical Practices for Treatment of HIV Infection," August 13, 2001. Available at: http://www.aidsinfo.nih.gov. Accessed September 5, 2001.
Hendeles SM, Galand N, and Schwers J, "Metabolism of Orally Administered D-norgestrel in Women,"Acta Endocrinol (Copenh), 1972, 71(3):557-68.
Holt VL, Scholes D, Wicklund KG, et al, "Body Mass Index, Weight, and Oral Contraceptive Failure Risk,"Obstet Gynecol, 2005, 105(1):46-52.
Orme ML, Back DJ, and Breckenridge AM, "Clinical Pharmacokinetics of Oral Contraceptive Steroids,"Clin Pharmacokinet, 1983, 8(2):95-136.
"Prescription Drug Products; Certain Combined Oral Contraceptives for Use as Postcoital Emergency Contraception,"Fed Regist, 1997, 62(37):8610-12 (Notice).
Shenfield GM and Griffin JM, "Clinical Pharmacokinetics of Contraceptive Steroids. An Update,"Clin Pharmacokinet, 1991, 20(1):15-37.
International Brand Names
Ovral® (CA)