Lynestrenol

Lynestrenol is a synthetic progestin that is taken orally. It can be used as a contraceptive or to treat menstrual cramps and endometriosis.

Indications and uses

Lynestrenol was one of the first synthetic progestins and was therefore used for contraception. It was administered in combination with an estrogen or alone in the form of the minipill. Since the approval of newer and better synthetic progestins, lynestrenol is no longer used for this purpose. It can also be used to treat menstrual cramps and endometriosis, requiring higher doses of the active ingredient.

Lynestrenol is administered orally as a mono- or combination preparation in the form of tablets. It is not approved for use in Germany or the USA. Only in Austria and the Netherlands are there preparations that are used as second-line agents for the treatment of endometriosis.

History

Lynestrenol was developed by the Dutch company Organon and first approved in the 1960s. It was a common contraceptive until the development of newer progestins such as levonorgestrel or gestodene.

Pharmacodynamics and mechanism of action

Progesterone is an endogenous steroid and progestin, a sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis in humans. Progesterone is mainly produced in the ovaries primarily in thecorpus luteum and is therefore also known as the corpusluteum hormone. However, it is also produced to a lesser extent in the adrenal cortex and, during pregnancy, in the placenta.

Progesterone is the major hormone of the corpus luteum and placenta. It acts on receptors in the uterus to transition the proliferative phase of the endometrium (uterine lining) to the secretory phase. It prepares the corpus luteum and endometrium for implantation of a fertilized egg. At the end of the luteal phase, the hormone causes a negative feedback loop, whereby to lower the levels of FSH (follicle stimulating hormone) and LH (luteinizing hormone). This prevents ovulation from occurring again and new eggs from maturing. The endometrium then prepares for pregnancy by forming new blood vessels and stimulating mucus secretion.

Lynestrenol itself does not bind to the progesterone receptor and is therefore inactive. It is a prodrug. It is rapidly and almost completely converted to the active progestogen norethisterone in the liver after oral administration due to first-pass metabolism. Therefore, its pharmacological activity of lynestrenol is essentially identical to that of norethisterone.

Pharmacokinetics

The conversion of lynestrenol to norethisterone is catalyzed by the CYP2C9, CYP2C19, and CYP3A4 enzymes.

Interactions

Due to its conversion by CYP450 enzymes, lynestrenol has significant potential for interactions. Primarily with drugs metabolized by CYP2C9, CYP2C19, and CYP3A4, there is potential for interactions.

Contraindications and precautions

Lynestrol should not be used in the following conditions:

• In pregnancy
• In case of severe liver dysfunction
• In case of bleeding from the vagina of unexplained origin
• In the presence of thromboembolic disease (myocardial infarction, thrombosis, coronary artery disease).
• In case of breast cancer
• In case of allergy to Lynestrol

Side effects

The following side effects may occur after the use of Lynestrenol:

Decrease in sexual desire (libido) Acne Absence of menstrual periods Abdominal pain Bleeding from the vagina (between normal menstrual periods), especially in the first two months Chloasma (pregnancy spots, ie. Depressive mood Diarrhea Breast tenderness Liver inflammation (hepatitis without jaundice) Vomiting Gallstones Jaundice Weight gain Skin rash Common (affects 1 to 10 people in 100) 100) Itching Headache Slightly increased blood sugar after a meal (decreased glucose tolerance) Migraine Nervousness Hives Edema (water retention in the tissues) Oily skin (seborrhea) Dizziness Hypersensitivity Nausea Change in fat and cholesterol levels in the blood Change in blood glucose levels (decreased glucose tolerance) and cholesterol levels in the blood Change in vaginal secretions Constipation Increased sweating

Pregnancy and breastfeeding

It is strictly contraindicated to be taken during pregnancy. It should also not be taken during lactation.