Warnings: If any of the conditions/risk factors mentioned as follows is present, the benefits of progestagen use should be weighed against the possible risks for each individual woman and discussed with the woman before she decides to start with Implanon NXT. In the event of aggravation, exacerbation or first appearance of any of these conditions, the woman should contact her HCP. The HCP should then decide on whether the use of Implanon NXT should be discontinued.
Carcinoma of the Breast: The risk for breast cancer increases in general with increasing age. During the use of (combined) oral contraceptives (OCs) the risk of having breast cancer diagnosed is slightly increased. This increased risk disappears gradually within 10 years after discontinuation of OC use and is not related to the duration of use, but to the age of the woman when using the OC. The expected number of cases diagnosed per 10 000 women who use combined OCs (up to 10 years after stopping) relative to never users over the same period have been calculated for the respective age groups to be: 4.5/4 (16-19 years), 17.5/16 (20-24 years), 48.7/44 (25-29 years), 110/100 (30-34 years), 180/160 (35-39 years) and 260/230 (40-44 years). The risk in users of contraceptive methods, which only contain progestagens, is possibly of similar magnitude as that associated with combined OCs. However, for these methods, the evidence is less conclusive. Compared to the risk of getting breast cancer ever in life, the increased risk associated with OCs is low. The cases of breast cancer diagnosed in OC users tend to be less advanced than in those who have not used OCs. The increased risk observed in OC users may be due to an earlier diagnosis, biological effects of the OC or a combination of both.
Liver Disease: When acute or chronic disturbances of liver function occur the woman should be referred to a specialist for examination and advice.
Thrombotic and Other Vascular Events: Epidemiological investigations have associated the use of combined OCs with an increased incidence of venous thromboembolism (VTE, deep venous thrombosis and pulmonary embolism). Although the clinical relevance of this finding for etonogestrel (the biologically active metabolite of desogestrel) used as a contraceptive in the absence of an estrogenic component is unknown, the implant should be removed in the event of a confirmed thrombosis. Removal of the implant should also be considered in case of long-term immobilization due to surgery or illness. Although Implanon NXT is a progestagen-only contraceptive, it is recommended to assess risk factors which are known to increase the risk of venous and arterial thromboembolism. Women with a history of thromboembolic disorders should be made aware of the possibility of a recurrence.
There have been postmarketing reports of serious arterial and venous thromboembolic events, including cases of pulmonary emboli (some fatal), deep vein thrombosis, myocardial infarction, and strokes, in women using etonogestrel implants. Implanon NXT should be removed in the event of a thrombosis.
Elevated Blood Pressure: If a sustained hypertension develops during the use of Implanon NXT, or if a significant increase in blood pressure does not adequately respond to antihypertensive therapy, Implanon NXT should be removed.
Carbohydrate and Lipid Metabolic Effects: Although progestagens may have an effect on peripheral insulin resistance and glucose tolerance, there is no evidence for a need to alter the therapeutic regimen in diabetics using progestagen-only contraceptives. However, diabetic women should be carefully observed while using progestagen-only contraceptives.
Women who are being treated for hyperlipidemia should be followed closely if they elect to use Implanon NXT. Some progestagens may elevate LDL levels and may render the control of hyperlipidemia more difficult.
Chloasma: Chloasma may occasionally occur, especially in women with a history of chloasma gravidarum. Women with a tendency to chloasma should avoid exposure to the sun or ultraviolet radiation whilst using Implanon NXT.
Body Weight: The contraceptive effect of Implanon NXT is related to the plasma levels of etonogestrel, which are inversely related to body weight, and decrease with time after insertion. The clinical experience in heavier women in the third year of use is limited. Therefore it cannot be excluded that the contraceptive effect in these women during the third year of use may be lower than for women of normal weight. HCPs may therefore consider earlier replacement of the implant in heavier women.
Complications of Insertion: Expulsion may occur especially if the implant is inserted not according to the instructions given in How to insert Implanon NXT under Dosage & Administration, or as a consequence of a local inflammation.
There have been reports of migration of the implant within the arm from the insertion site, which may be related to a deep insertion (see also How to insert Implanon NXT under Dosage & Administration), or external forces (e.g. manipulation of the implant or contact sports). There also have been rare postmarketing reports of implants located within the vessels of the arm and the pulmonary artery, which may be related to deep insertions or intravascular insertion. In cases where the implant has migrated within the arm from the insertion site, localization may be more difficult and removal may require a minor surgical procedure with a larger incision or a surgical procedure in an operating room. In cases where the implant has migrated to the pulmonary artery, endovascular or surgical procedures may be needed for removal (see also How to remove Implanon NXT under Dosage & Administration). If at any time the implant cannot be palpated, it should be localized and removal is recommended. If the implant is not removed, contraception and the risk of progestagen-related undesirable effects may continue beyond the time desired by the woman.
Ovarian Cysts: With all low-dose hormonal contraceptives, follicular development may occur and occasionally the follicle may continue to grow beyond the size it would attain in a normal cycle. Generally, these enlarged follicles disappear spontaneously. Often, they are asymptomatic; in some cases they are associated with mild abdominal pain. They rarely require surgical intervention.
Ectopic Pregnacies: The protection with traditional progestagen-only contraceptives against ectopic pregnancies is not as good as with combined OCs, which has been associated with the frequent occurrence of ovulations during the use of these methods. Despite the fact that Implanon NXT will consistently inhibits ovulation, ectopic pregnancy should be taken into account in the differential diagnosis if the woman gets amenorrhea or abdominal pain.
Other Conditions: The following conditions have been reported both during pregnancy and during sex steroid use, but an association with the use of progestagens has not been established: jaundice and/or pruritus related to cholestasis; gallstone formation; porphyria; systemic lupus erythematosus; hemolytic uraemic syndrome; Sydenham's chorea; herpes gestationis; otosclerosis-related hearing loss and (hereditary) angioedema.
Medical examination/consultation: Prior to the initiation or reinstitution of Implanon NXT a complete medical history (including family medical history) should be taken and pregnancy should be excluded. Blood pressure should be measured and a physical examination should be performed, guided by the contraindications (see Contraindications) and warnings (see previously mentioned Warnings). It is recommended that the woman returns for a medical check-up three months after insertion of Implanon NXT. During this check-up, the blood pressure should be measured and an enquiry should be made after any questions, complaints or the occurrence of undesirable effects. The frequency and nature of further periodic checks should be adapted to the individual woman, guided by clinical judgement.
Women should be advised that Implanon NXT does not protect against HIV (AIDS) and other sexually transmitted diseases.
Reduced efficacy with concomitant medications: The efficacy of Implanon NXT may be reduced when concomitant medications that decrease the plasma concentration of etonogestrel are used (see Interactions).
Changes in the menstrual bleeding pattern: During the use of Implanon NXT, women are likely to have changes in their menstrual bleeding pattern. These may include changes in bleeding frequency (absent, less, more frequent or continuous), intensity (reduced or increased) or duration. Amenorrhea was reported in about 1 of 5 women while another 1 of 5 women reported frequent and/or prolonged bleeding. Dysmenorrhea tended to improve while using Implanon NXT. The bleeding pattern experienced during the first three months is broadly predictive of future bleeding patterns for many women. Information, counseling and the use of a bleeding diary can improve the woman's acceptance of a bleeding pattern. Evaluation of vaginal bleeding should be done on an ad hoc basis and may include an examination to exclude gynecological pathology or pregnancy.
Broken or bent implant: There have been reports of broken or bent implants, which may be related to external forces (e.g. manipulation of the implant or contact sports) while in the patient's arm. There have also been reports of migration of a broken implant fragment within the arm. Based on in vitro data, when the implant is broken or bent, the release rate of etonogestrel may be slightly increased. This change is not expected to have clinically meaningful effects.
When an implant is removed, it is important to remove it in its entirety (see How to remove Implanon NXT under Dosage & Administration).
Effects on ability to drive and use machines: No observed effects.