etonogestrel and ethinyl estradiol vaginal ring

Action

Inhibits ovulation by altering cervical mucosa and endometrium of uterus. This inhibition prevents sperm from entering the uterus, thereby preventing implantation.

Availability

Vaginal ring: 0.12 mg etonogestrel and 0.015 mg ethinyl estradiol delivered daily over 3 weeks

Indications and dosages

➣ To prevent pregnancy

Adults: Place one ring into vagina and leave in place for 3 weeks, then remove for 1 week. Insert next ring on same day of week as in previous cycle.

Contraindications

• Hypersensitivity to drug or its components

• Breast and uterine cancers or other known or suspected estrogen-dependent neoplasms

• Valvular heart disease with complications

• Thromboembolic disease (current or previous)

• Severe hypertension

• Diabetes with vascular involvement

• Headache with focal neurologic symptoms

• Hepatic tumors, cholestatic jaundice

• Major surgery with prolonged immobilization

• Undiagnosed vaginal bleeding

• Patients older than age 35 who smoke more than 15 cigarettes daily

• Pregnancy or breastfeeding

Precautions

Use cautiously in:

• underlying cardiovascular disease, severe hepatic or renal disease, asthma, bone disease, migraines, breast disease, seizures, sexually transmitted diseases

• family history of breast or genital tract cancers.

Administration

• Be aware that the best way to insert ring is with patient lying down, squatting, or standing and one leg raised.

Adverse reactions

CNS: headache, migraines, dizziness, lethargy, depression, increased risk of cerebrovascular accident, seizures

CV: hypertension, myocardial infarction, thromboembolism

EENT: worsening of myopia or astigmatism

GI: nausea, vomiting, abdominal cramps, bloating, pancreatitis

GU: amenorrhea, dysmenorrhea, cervical erosion, breakthrough bleeding, loss of libido, vaginal candidiasis, erectile dysfunction, testicular atrophy, breast tenderness, breast enlargement or secretion, increased risk of endometrial and breast cancer

Hepatic: cholestatic jaundice, hepatic adenoma

Metabolic: sodium and fluid retention

Respiratory: pulmonary embolism

Other: increased appetite, weight changes, edema

Interactions

Drug-drug. Acetaminophen: decreased acetaminophen blood level

Anti-infectives, barbiturates, carbamazepine, fosphenytoin, rifampin: decreased contraceptive efficacy

Corticosteroids: increased corticosteroid effects

Cyclosporine: increased risk of cyclosporine toxicity

CYP3A4 inhibitors (such as itraconazole, ketoconazole): increased hormone levels

Dantrolene, other hepatotoxic drugs: increased risk of hepatotoxicity

Hypoglycemics, warfarin: altered requirements for these drugs

Miconazole (vaginal capsules): increased hormone levels

Phenytoin: loss of seizure control

Protease inhibitors: increased contraceptive metabolism

Tamoxifen: interference with tamoxifen efficacy

Tricyclic antidepressants: reduced antidepressant effects

Drug-diagnostic tests. Antithrombin III, folate, low-density lipoproteins, pyridoxine, total cholesterol: decreased levels

Cortisol; factors VII, VIII, IX, and X; glucose; high-density lipoproteins; phospholipids; prolactin; prothrombin; sodium; triglycerides: increased levels

Drug-food. Caffeine: increased caffeine blood level

Drug-herbs. Black cohosh: increased risk of adverse reactions

Red clover: interference with contraceptive action

Saw palmetto: antiestrogenic effects St. John's wort: decreased contraceptive blood level and effects

Drug-behaviors. Smoking: increased risk of adverse cardiovascular reactions

Patient monitoring

See Monitor CNS status. Report adverse CNS reactions immediately.

See Assess blood pressure frequently. If significant elevation of blood pressure occurs, discontinue NuvaRing.

• Monitor patient for depression.

See Watch for jaundice and liver engorgement; be aware that combination hormonal contraceptives may worsen existing gallbladder disease and may accelerate development of this disease in previously asymptomatic women. Discontinue drug if jaundice develops.

See Be aware that retinal thrombosis has been associated with the use of hormonal contraceptives. Discontinue NuvaRing if unexplained partial or complete loss of vision, onset of proptosis or diplopia, papilledema, or retinal vascular lesions occur. Take appropriate diagnostic and therapeutic measures immediately.

• Monitor glucose, calcium, and electrolyte levels and lipid profile.

Patient teaching

• Explain that for continued contraception, a new implant must be inserted exactly 1 week after old one is removed, even if patient is menstruating.

• Tell patient to insert and remove ring on same day of week and at same time of day.

• Tell patient that if ring slips out, she should replace it within 3 hours to ensure adequate contraceptive protection.

• Inform patient that smoking during therapy may increase risk of blood clots, phlebitis, and stroke.

See Tell patient to immediately report signs and symptoms of depression, sudden chest pain, difficulty breathing, or yellowing of skin or eyes.

See Tell patient to stop drug and immediately report unexplained partial or complete loss of vision, onset of proptosis or diplopia, papilledema, or retinal vascular lesions.

• Teach patient how to perform breast self-examinations. Emphasize importance of monthly checks.

• Tell patient that this product doesn't protect against HIV infection (AIDS) and other sexually transmitted diseases.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.