Implanon- Implantable progestin for pregnancy control

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Company:

Organon

Pharmacologic class:

Progestin

Active ingredient:

Etonogestrel 68 mg; implantable rod; latex-free.

Indication:

Subdermal implant for long-term (up to three years) contraception.

Pharmacology:

Implanon is a single implantable rod that contains the synthetic progestin, etonogestrel, which is a metabolite of desogestrel. The contraceptive effect of Implanon is a result of several mechanisms that include the suppression of ovulation and changes in the endometrium and cervical mucus.

Following subdermal placement, etonogestrel is released slowly over a period of three years, after which time it must be removed. Mean serum levels are reached within the first few weeks and decrease gradually over time. After three years, the implant may be replaced if continued contraception is desired.

Clinical trials:

In studies involving 923 women aged 18-35 years at entry, six pregnancies during 20,648 cycles of use were reported. Two pregnancies occurred in each of years 1, 2, and 3, and each conception was likely to have occurred shortly before or within two weeks after removal of the implant.

The cumulative Pearl Index was 0.38 pregnancies per 100 women-years of use. These trials excluded women who weighed >130% of their ideal body weight and those chronically taking medications that induce hepatic enzymes. Under these conditions, Implanon may be less effective.

Adults:

Insert one implant subdermally in the inner side of upper (nondominant) arm. Remove no later than three years after insertion.

Children:

Premenarchal: not applicable.

Contraindications:

Breast carcinoma. Undiagnosed abnormal genital bleeding. Active liver disease. Liver tumors. Pregnancy. Thromboembolic disease.

Precautions:

Overweight women (may be less effective). Do complete physical exam before insertion and at least annually. Exclude pregnancy (see literature for switching from other contraceptive methods); use backup contraception if appropriate. See literature for insertion and removal technique; perform only if properly qualified.

Remove implant if jaundice or thrombotic event occurs, or if a pregnancy is maintained; consider removing implant in prolonged immobilization. Hypertension. Renal disease. Depression. Monitor diabetes, hyperlipidemias. Nursing mothers: may use after fourth postpartum week.

Interactions:

Chronic antiepileptic or other potent hepatic enzyme-inducing drugs (e.g., barbiturates, phenytoin, carbamazepine, rifampin, felbamate, modafinil): not recommended. May be antagonized by other hepatic enzyme inducers (e.g., St. John’s wort, protease inhibitors); use non-hormonal contraception. Levels increased by ketoconazole, itraconazole, other hepatic enzyme inhibitors. May affect measurement of sex-hormone-binding globulin, thyroxine.

Adverse reactions:

Headache, vaginitis, weight increase, acne, mastodynia, menstrual irregularities (e.g., amenorrhea, changes in bleeding patterns), abdominal pain (exclude ectopic pregnancy), leukorrhea, dizziness, back pain, emotional lability, nausea, depression, insertion site pain; thrombotic events, others (see literature).

Note:

Provide adequate counseling. Obtain signed written consent (see literature).

How supplied:

Rod implant—1.

For more information, call 877.IMPLANON.

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