Norlyda

Generic name:norethindrone
Dosage form: tablets
Drug classes:Contraceptives, Progestins

Medically reviewed by Drugs.com. Last updated on Apr 21, 2022.

Norlyda Description

Each white Norlyda (norethindrone tablet, USP) provides a continuous oral contraceptive regimen of 0.35 mg norethindrone, USP daily, and the inactive ingredients include hydrogenated cottonseed oil, hydroxypropyl cellulose, hypromellose, lactose monohydrate, magnesium stearate, povidone, pregelatinized starch, talc, and titanium dioxide.

Norethindrone, USP is a white to creamy white, odorless, crystalline powder practically insoluble in water; soluble in chloroform and in dioxane; sparingly soluble in alcohol; slightly soluble in ether.

The chemical name for norethindrone is 17-Hydroxy-19-Nor-17α-pregn-4-en-20-yn-3-one. The structural formula follows:

norethindrone

Therapeutic class = oral contraceptive.

Norlyda - Clinical Pharmacology

1. Mode of Action. Norlyda progestin-only oral contraceptives prevent conception by suppressing ovulation in approximately half of users, thickening the cervical mucus to inhibit sperm penetration, lowering the mid-cycle LH and FSH peaks, slowing the movement of the ovum through the fallopian tubes, and altering the endometrium.

2. Pharmacokinetics.

Absorption: Norethindrone is rapidly absorbed with maximum plasma concentrations occurring within 1 to 2 hours after norethindrone tablets administration (see Table 1). Norethindrone appears to be completely absorbed following oral administration; however, it is subject to first pass metabolism resulting in an absolute bioavailability of approximately 65%.

Figure 1: Mean ± SD Norethindrone Plasma Concentrations Following Norethindrone Administration.

Peak plasma concentrations occur approximately 1 hour after administration (mean Tmax 1.2 hours). The mean (SD) Cmax was 4816.8 (1532.6) pg/mL and generally occurred within 1 hour (mean) of tablet administration, ranging from 0.5 to 2 hours. The mean (SD) Cavg