Desogestrel

Desogestrel is a synthetic progestin used primarily in hormonal contraception. It is commonly found in progestin-only pills (POPs) or combined with estrogens in combined oral contraceptives (COCs). Desogestrel was approved by the U.S. Approved by the Food and Drug Administration (FDA) in 1992 as a component of combined oral contraceptives, desogestrel may also help prevent pregnancy by altering the uterine lining and increasing the thickness of cervical mucus.

BRAND NAMES:

Cerazette - Cerazette is available as oral tablet containing 0.075mg of desogestrel as the main active ingredient.

Primepill D- Available in the form of oral tablet containing 0.15mg of desogestrel and 0.03mg of ethinylestradiol.

MECHANISM OF ACTION:

Desogestrel is a synthetic progestin commonly used in hormonal contraceptives, including both progestin-only pills and combined oral contraceptives. Its primary mode of action is the suppression of ovulation. Desogestrel acts on the hypothalamic-pituitary-ovarian axis by suppressing the secretion of gonadotropin-releasing hormone (GnRH), which in turn reduces the levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This suppression prevents the mid-cycle LH surge necessary for ovulation. In addition to inhibiting ovulation, desogestrel thickens cervical mucus, creating a physical barrier that makes it more difficult for sperm to enter the uterus and reach an egg. It also induces changes in the endometrial lining, rendering it less receptive to implantation. Desogestrel is a prodrug, metabolized in the body to its active form, etonogestrel, and is characterized by low androgenic activity, making it a favourable option for individual’s sensitive to androgen-related side effects. Among progestin-only pills, desogestrel is notable for its consistent suppression of ovulation, a feature not always shared by older formulations.

PHARMACOKINETICS:

Absorption: It takes 1 – 2 hours to reach its peak plasma concentration after oral administration. The oral bioavailability is approximately 70 -80%.

Distribution: The volume of distribution of etonogestrel is approximately 1.5–2 L/kg, suggesting widespread distribution in body tissues.

Metabolism: Desogestrel itself is inactive and undergoes rapid and complete first-pass hepatic metabolism to form etonogestrel, the active metabolite. The conversion involves oxidation by cytochrome P450 enzymes. Etonogestrel is further metabolized in the liver by hydroxylation and conjugation before excretion.

Excretion: The metabolites are mainly excreted in the urine (approximately 60%), while the remainder is eliminated through the feces (around 40%).

PHARMACODYNAMICS:

Desogestrel exerts its pharmacodynamic effects primarily through its active metabolite, etonogestrel, which binds with high affinity to progesterone receptors in target tissues. This interaction mimics the action of natural progesterone, leading to suppression of the hypothalamic-pituitary-gonadal axis. Specifically, it inhibits the release of gonadotropin-releasing hormone (GnRH), which reduces the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thereby preventing the LH surge necessary for ovulation. In addition to ovulation suppression, etonogestrel thickens cervical mucus, making it more difficult for sperm to penetrate, and alters the endometrial lining to make it less suitable for implantation. Desogestrel has minimal androgenic, estrogenic, or glucocorticoid activity, resulting in fewer hormone-related side effects compared to older progestins. Its contraceptive effects are dose-dependent, begin shortly after initiation, and are quickly reversible upon discontinuation, with ovulatory function typically resuming within a few weeks.

DOSAGE AND ADMINISTRATION:

Desogestrel tablets are commonly available in combination with ethinyl estradiol as oral tablets for consumption. The medicine should be taken at the same time each day.0.15g of desogestrel and 0.03mg ethinyl estradiol tablets available in the market as oral tablets.

1 tablet should be taken orally once a day from day 1 to 21. From day 22 to 28, one inert tablet should be taken orally once a day.

DRUG INTERACTIONS:

Below medicines should be avoid while taking desogestrel or should discuss with the doctor before taking Desogestrel medicines.

Anti-epilepsy medicines – Primidone, Phenytoin, Carbamazepine
Tuberculosis – Rifampicin

CONTRAINDICATIONS:

Desogestrel is contraindicated in patients who are hypersensitive to the drug or any of its excipients, as well as in those with kidney disease or breast cancer.

ADVERSE EFFECTS: