Etonogestrel

When ATH:
G03AC08

Pharmacological action

Contraceptive.

Etonogestrel, a derivative of 19-nortestosterone, It binds to the progesterone receptor in target organs.

At the heart of contraception the effect of etonogestrel are various mechanisms, the most significant of which are the inhibition of ovulation. Pearl Index is the drug 0.765.

In addition to the contraceptive action of etonogestrel it has a positive effect on the menstrual cycle. Against the background of etonogestrel cycle becomes more regular, menstruation occur less painful, with a lower intensity of bleeding, which in turn can help reduce the frequency of iron deficiency. Besides, there is evidence of reducing the risk of endometrial cancer and ovarian cancer.

Pharmacokinetics

Absorption

Etonogestrel is rapidly absorbed vaginal mucosa. C max этоногестрела, approximately equal to 1700 pg / ml, It is achieved after about a week after the introduction of the ring. Serum is subject to small fluctuations and slowly reaches 1400 pg / ml after 3 weeks. The absolute bioavailability of approximately 100%.

Distribution

Etonogestrel binds to serum albumin and globulin, sex hormone binding (SHBG). CEO этоногестрела 2.3 l / kg.

Metabolism

Etonogestrel metabolized by hydroxylation to form and recover sulfate and glucuronide conjugates. The serum clearance is approximately 3.5 l /.

Deduction

Reducing the concentration of serum etonogestrel is biphasic. T 1/2 β-phase is about 29 no. Etonogestrel and its metabolites are excreted in urine and bile in the ratio 1.7:1. T 1/2 metabolites about 6 days.

Testimony

Contraception for women.

Side effect

Headache, acne, weight gain, pain in the breast, hair loss, depression, emotional lability, change in sexual desire, stomach ache, dysmenorrhoea. Rarely, increased blood pressure. After the introduction of the implant may occur slight local irritation, pain or itching. Rarely is a scar.

Contraindications

Progestogen-dependent tumors, thrombo-embolic active disorder, current liver disease or a history, If liver function tests have not come back to normal, existing or suspected pregnancy, bleeding from the vagina of unknown etiology, Hypersensitivity to the drug.

Cautions

Caution is needed in liver disease, cholestatic jaundice. If necessary, surgical treatment should be stopped. During the duration of the implant with etonogestrel not to appoint other hormonal contraceptives.

Drug Interactions

Griseofulvin, barbiturates, phenytoin, prymydon, carbamazepine and rifampicin reduces the effectiveness of etonogestrel by inducing liver enzymes. The effect appears after induction 2-3 weeks of, but it takes at least 4 weeks after the termination of their admission.