ESTROGEN-PROGESTIN COMBINATIONS (CONTRACEPTIVES)

ESTROGEN-PROGESTIN COMBINATIONS (CONTRACEPTIVES) Oral Monophasic: Apri, Alesse, Aviane, Balziva, Brevicon, Cryselle, Demulen, Desogen, Gencept, Junel, Lessina, Levlite, Levora, Loestrin, Lo/Ovral, Low-Ogestrel, Microgestin, Modicon, Nordette, Norethin,, Norinyl, Nortrel, Ogestrel, Ortho-Cept, Ortho-Cyclen, Ortho-Novum, Ovcon, Portia, Previfem, Seasonale, Sprintec, Yasmin, Yaz, Zovia Biphasic: Kariva, Mircette, Ortho-Novum 10/11 Triphasic: Aranelle, Cyclessa, Enpresse, Estrostep, Estrostep Fe, Lybrel, Ortho-Novum 7/7/7, Ortho Tri-Cyclen, Ortho Tri-Cyclen Lo, Tri-Norinyl, Tri-Previfem, Tri-Sprintec, Triphasil, Trivora, Velivet Postcoital Contraceptives: Plan B, Preven Transdermal Ortho Evra Intravaginal NuvaRing Classifications: hormone; estrogen-progestin combinations; Therapeutic: contraceptive Prototype: Estradiol, Norgestrel Pregnancy Category: X

Availability

Combination oral contraceptives contain one of the following estrogens and one of the following progestins. Estrogen: Ethinyl estradiol 10 mcg, 20 mcg, 25 mcg, 30 mcg, 35 mcg, 40 mcg, 50 mcg; mestranol 50 mcg; Progestin: Desogestrel 0.15 mg; drospirenone 3 mg; ethynodiol diacetate 1 mg; levonorgestrel 0.05 mg, 0.075 mg, 0.1 mg, 0.125 mg, 0.15 mg, 0.25 mg, 0.75 mg; norethindrone 0.4 mg, 0.5 mg, 0.75 mg, 1 mg; norethindrone acetate 1 mg, 1.5 mg; norgestimate 0.18 mg, 0.215 mg, 0.25 mg; norgestrel 0.3 mg, 0.5 mg; Transdermal: Norelgestromin 6 mg/0.75 mg ethinyl estradiol patch; Vaginal: Etonogestrel 11.7 mg/2.7 mg ethinyl estradiol vaginal insert

Action

Three types of estrogen-progestin combinations are available: (1) monophasic, fixed dosage of estrogen-progestin throughout the cycle; (2) biphasic, amount of estrogen remains the same throughout cycle, less progestin in first half of cycle and increased progestin in second half; (3) triphasic, estrogen amount is the same or varies throughout cycle, progestin amount varies.

Therapeutic Effect

Fixed combination of estrogen and progestin produces contraception by preventing ovulation and rendering reproductive tract structures hostile to sperm penetration and zygote implantation.

Uses

To prevent conception and to treat hypermenorrhea and endometriosis; postcoital contraceptive or "morning after pill"; moderate acne in females ≥15 y (Tri-Cyclen).

Contraindications

Familial or personal history of or existence of breast or other estrogen-dependent neoplasm, recurrent chronic cystic mastitis, history of or existence of thrombophlebitis or thromboembolic disorders, cerebral vascular or coronary artery disease, MI, serious hepatic dysfunction, hepatic neoplasm, family history of hepatic porphyria, undiagnosed abnormal vaginal bleeding, women age 40 and over, adolescents with incomplete epiphyseal closure; pregnancy (category X), lactation, missed abortion.

Cautious Use

History of depression, preexisting hypertension, or cardiac or renal disease; impaired liver function, history of migraine, convulsive disorders, or asthma; multiparous women with grossly irregular menses, diabetes, or familial history of diabetes; gallbladder disease, lupus erythematosus, rheumatic disease, varicosities, smokers.

Route & Dosage

Contraception Adult: PO 1 active tablet daily for 21 d, then placebo tablet or no tablets for 7 d, repeat cycle Continuous regimen (Seasonale) 1 tablet daily x 84 consecutive days. Wait 7 d for withdrawal bleeding before starting next cycle Topical Apply one patch once weekly for 3 wk, then have 1 wk patch-free before repeating the cycle Intravaginal Insert 1 ring on or before day 5 of the cycle. Remove ring after 3 wk, followed by a 1 wk rest. Then insert new ring. Postcoital Contraception (Plan B, Preven, Ovral) Adult: PO Ovral, 2 tablets within 72 h of intercourse, then 2 tablets 12 h later; 1 (Plan B) or 2 (Preven) tablets within 72 h of unprotected intercourse, take second dose of 1 (Plan B) or 2 (Preven) tablets 12 h later

Administration

• Give without regard to meals.
• Do not exceed 24-h intervals between the daily doses; taking with a meal or at bedtime is a helpful reminder.

Adverse Effects (≥1%)

Body as a Whole: Paresthesias. CV: Malignant hypertension, thrombotic and thromboembolic disorders, mild to moderate increase in BP, increase in size of varicosities, edema. Endocrine: Estrogen excess (nausea, bloating, menstrual tension, cervical mucorrhea, polyposis, chloasma, hypertension, migraine headache, breast fullness or tenderness, edema); estrogen deficiency (hypomenorrhea, early or mid-cycle breakthrough bleeding, increased spotting); progestin excess (hypomenorrhea, breast regression, vaginal candidiasis, depression, fatigue, weight gain, increased appetite, acne, oily scalp, hair loss); progestin deficiency (late-cycle breakthrough bleeding, amenorrhea). GI: Nausea, cholelithiasis, gallbladder disease, cholestatic jaundice, benign hepatic adenomas; diarrhea, constipation, abdominal cramps. Metabolic: Decreased glucose tolerance, pyridoxine deficiency (see also diagnostic test interferences), acute intermittent porphyria. Skin: Rash (allergic), photosensitivity (photoallergy or phototoxicity), irritation from patch. Special Senses: Unexplained loss of vision, optic neuritis, proptosis, diplopia, change in corneal curvature (steepening), intolerance to contact lenses, retinal thrombosis, papilledema. Urogenital: Ureteral dilation, increased incidence of urinary tract infection, hemolytic uremia syndrome, renal failure, increased risk of congenital anomalies, decreased quality and quantity of breast milk, dysmenorrhea, increased size of preexisting uterine fibroids, menstrual disorders. Foreign body sensation, coital problems, device expulsion, vaginal discomfort, vaginitis, leukorrhea from ring.

Diagnostic Test Interference

ORAL CONTRACEPTIVES (OCs) increase BSP retention, prothrombin and coagulation factors II, VII, VIII, IX, X; platelet agregability, thyroid-binding globulin, PBI, T₄: transcortin; corticosteroid, triglyceride and phospholipid levels; ceruloplasmin, aldosterone, amylase, transferrin; renin activity, vitamin A. OCs decrease antithrombin III, T₃ resin uptake, serum folate, glucose tolerance, albumin, vitamin B₁₂ and reduce the metyrapone test response.

Interactions

Drug: Aminocaproic acid may increase clotting factors, leading to hypercoagulable state; barbiturates, anticonvulsants, antibiotics, rifampin, antifungals reduce efficacy of OCs and increase incidence of breakthrough bleeding and risk of pregnancy. May decrease efficacy of lamotrigine. Herbal: St. John's wort may decrease efficacy of OCs.

Pharmacokinetics

Absorption: Oral: Readily from GI tract; or from transdermal patch placed on abdomen, buttock, upper outer arm and upper torso (excluding breast). Vaginal insert: norgestrel 100% absorbed, ethinyl estradiol 56% absorbed. Peak: Patch: 48 h. Duration: Patch: 1 wk. Distribution: Widely distributed; crosses placenta; small amount distributed into breast milk. Metabolism: In liver. Elimination: In urine and feces. Half-Life: 6–45 h oral. Following removal of the patch: norelgestromin 28 h, ethinyl estradiol 17 h; vaginal ring: norgestrel 29 h; ethinyl estradiol 45 h.

Nursing Implications

Assessment & Drug Effects

• Take complete medical and family history prior to initiation of OC therapy. Physical exam: Baseline and periodic BP, breasts, abdomen, pelvis, Pap smear, and other relevant tests.
• Rule out pregnancy before OC therapy is begun.
• Check BP periodically. In some women, changes in BP occur within each cycle; in others, slow increase of pressure, particularly diastolic, over several months is significant. Drug-induced BP elevation is usually reversible with cessation of OC.
• Nausea with or without vomiting occurs in approximately 10% of patients during the first cycle and is reportedly one of the major reasons for voluntary discontinuation of therapy. Most adverse effects tend to disappear in third or fourth cycle of use. Instruct patient to report symptoms that persist after fourth cycle. Dose adjustment or a different product may be indicated.
• Hirsutism and loss of hair are reversible with discontinuation of OC or by change of selected combination.
• Acne may improve, worsen, or develop for first time. In women on OC for at least 1 y, postcontraceptive acne sometimes occurs 3–4 mo after stopping drug and may continue for 6–12 mo.
• Anovulation or amenorrhea following termination of OC regimen may persist more than 6 mo. The user with pretreatment oligomenorrhea or secondary amenorrhea is most apt to have oversuppression syndrome.

Patient & Family Education

• Use an additional method of birth control during the first week of the initial cycle.
• Missed dose: Take tablet as soon as remembered or take 2 tablets the next day. If 2 consecutive tablets are omitted, take 2 tablets daily for the next 2 d, then resume the regular schedule. If 3 consecutive tablets are missed, begin a new compact of tablets, starting 7 d after last tablet was taken.
• Use an additional form of birth control for 7 d after 2 missed doses; 14 d after 3 missed doses.
• Ovulation is unlikely with omission of 1 daily dose; however, the possibility of escaped ovulation, spotting, or breakthrough bleeding increases with each missed dose.
• Discontinue medication if intra-cycle bleeding resembling menstruation occurs. Begin taking tablets from a new compact on day 5. If bleeding persists, see physician.
• Transdermal patches: Apply only one patch at a time and never cut or otherwise alter a patch prior to application.
• See physician to rule out pregnancy if 2 consecutive periods are missed, before continuing on OC.
• Do not skip scheduled visits for physical checkups while on OC therapy. Learn breast self-examination and do every month.
• Record frequent weight checks to permit early recognition of fluid retention.
• Understand the increased risk of thromboembolic and cardiovascular problems and increased incidence of gallbladder disease with OC use. Be alert to manifestations of thrombotic or thromboembolic disorders: severe headache (especially if persistent and recurrent), dizziness, blurred vision, leg or chest pain, respiratory distress, unexplained cough. Discontinue drug if any of these symptoms appear and report them promptly to physician.
• Report sudden abdominal pain immediately to physician in order to rule out ectopic pregnancy.
• Be aware that ophthalmic sequelae can occur as soon as 24 h after initiation of OC. Stop drug and contact physician if unexplained partial or complete, sudden or gradual loss of vision, protrusion of eyeballs (proptosis), or diplopia occurs.
• Leukorrhea (increased clear discharge) is an expected physical reaction to the OC; however, if OC use is accompanied by vaginal itching and irritation, report to physician promptly to rule out candidiasis.
• Monitor urine and blood glucose closely if diabetic. Adjustment of antidiabetic medication may be necessary.
• Be aware that smokers using OC have a fivefold greater risk of fatal MI than nonsmoker OC users and a tenfold greater risk than non-OC users who are nonsmokers. The risk increases with age (marked in women >35 y) and with heavy smoking (15 or more cigarettes/d).
• Oral contraception can be started immediately after delivery in the nonlactating mother.
• Use alternate method of birth control when breast feeding until infant is weaned.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug