• Prevention of pregnancy.

Contraindicated in:

• Hypersensitivity
• Known or suspected pregnancy
• Active liver disease
• Current/past history of thromboembolism
• Active liver disease or hepatic tumors
• Chronic use of drugs that induce liver enzymes
• Undiagnosed abnormal genital bleeding
• Known/suspected breast cancer.

Use Cautiously in:

• OB: Lactation (may be used after 4th postpartum week)
• Obesity (contraceptive may be less effective)
• Conditions associated with fluid retention
• Hypertension
• Cigarette smoking or age >35 (↑ risk of thromboembolic events)
• Pedi: Safe use in children <18 yr is not established; should not be used before menarche.

CNS: depression, dizziness, emotional lability, headache, nervousness.

CV: THROMBOEMBOLIC EVENTS, hypertension.

GI: hepatic adenomas.

GU: dysmenorrhea, irregular/unpredictable menses, ↑ risk of ectopic pregnancy, ovarian cysts.

Derm: acne.

Endo: breast pain, leukorrhea.

Local: implant site reactions.

Metab: weight gain.

MS: back pain.

Drug-Drug:

• Barbiturates, grisofulvin, rifampin, phenytoin, carbamazepine, oxcarbazepine, topiramate, modafinil induce liver enzymes and may ↓ contraceptive effectiveness.
• Protease inhibitors may alter blood levels and effects.
• Inhibitors of liver enzymes including itraconazole and ketoconazole may ↑ blood levels.

Drug-Natural Products:

• St. John's wort induces liver enzymes and may ↓ contraceptive effectiveness.

• Subdermally implantable rod: 68 mg;

• Subdermal (Adults): 1 68-mg implant, contraceptive effect lasts for 3 yr.

Implanon

• Suppresses ovulation, increases viscosity of cervical mucosa and alters endometrium.

• Prevention of pregnancy.

Therapeutic Classification: contraceptive hormones

Pharmacologic Classification: progestins

Absorption: Reliably, constantly and slowly absorbed (100% bioavailable).

Distribution: Crosses the placenta and enters breast milk.

Metabolism/Excretion: Mostly metabolized by the liver.

Half-life: 25 hr.

• Instruct patient on information on insertion and removal and provide a copy of the Patient Labeling. Patient should fill out and retain the User Card so that she will have a record of the location and when it should be removed. Advise patient to re-start contraception immediately after removal of Implanon, if she still needs to prevent pregnancy.
• Instruct patient to notify health care profession of all Rx, OTC, and herbal products she is taking or intends to take. Advise patient that a second method of birth control should also be used during each cycle in which any of the following are used: Oral contraceptives — ampicillin, antiretroviral protease inhibitors, ketoconazole, itraconazole, barbiturates, carbamazepine, felbamate, modafinil, oxcarbazepine, penicillin V, phenylbutazone, phenytoin, rifampin, sulfonamides, tetracyclines, topiramate, valproic acid, and St. John's wort.
• If nausea becomes a problem, advise patient that eating solid food often provides relief.
• Inform patient that Implanon may cause unpredictable changes in vaginal bleeding patterns (changes in bleeding frequency and duration or amenorrhea). Advise patient to notify health care professional if these changes become extreme or persist.
• May cause dizziness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
• Advise patient to report signs and symptoms of fluid retention (swelling of ankles and feet, weight gain), thromboembolic disorders (pain, swelling, tenderness in extremities, headache, chest pain, blurred vision), mental depression, hepatic dysfunction (yellowed skin or eyes, pruritus, dark urine, light-colored stools), or abnormal vaginal bleeding. Women with a strong family history of breast cancer, fibrocystic breast disease, abnormal mamograms or cervical dysplasia should be monitored for breast cancer at least yearly. Implanon should be removed from patients who develop jaundice significant depression.
• Instruct patient to notify health care professional if pregnancy is suspected.
• Caution patient that cigarette smoking during estrogen therapy may increase risk of serious side effects, especially for women over age 35.
• Advise contact lens wearers who develop visual changes or changes in lens tolerance to be examined by an ophthalmologist.
• Caution patients to use sunscreen and protective clothing to prevent increased pigmentation.
• Caution patient that oral contraceptives do not protect against HIV or other sexually transmitted diseases.
• Advise patient to notify health care professional of medication regimen before treatment or surgery.
• Emphasize the importance of routine follow-up physical exams including BP; breast, abdomen, and pelvic examinations; and Papanicolaou smears every 6–12 mo.

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