Deblitane - Norethindrone prescribing information
Cigarette smoking greatly increases the possibility of suffering heart attacks and strokes. Women who use oral contraceptives are strongly advised not to smoke.
INDICATIONS AND USAGE
1. Indications. Progestin-only oral contraceptives are indicated for the prevention of pregnancy.
2. Efficacy. If used perfectly, the first-year failure rate for progestin-only oral contraceptives is 0.5%. However, the typical failure rate is estimated to be closer to 5%, due to late or omitted pills. The following table lists the pregnancy rates for users of all major methods of contraception.
DOSAGE AND ADMINISTRATION
To achieve maximum contraceptive effectiveness, DEBLITANE TM must be taken exactly as directed. One tablet is taken every day, at the same time. Administration is continuous, with no interruption between pill packs. See PATIENT LABELING for detailed instructions.
CONTRAINDICATIONS
Progestin-only oral contraceptives (POPs) should not be used by women who currently have the following conditions:
- Known or suspected pregnancy
- Known or suspected carcinoma of the breast
- Undiagnosed abnormal genital bleeding
- Hypersensitivity to any component of this product
- Benign or malignant liver tumors
- Acute liver disease
ADVERSE REACTIONS
- Menstrual irregularity is the most frequently reported side effect.
- Frequent and irregular bleeding are common, while long duration of bleeding episodes and amenorrhea are less likely.
- Headache, breast tenderness, nausea, and dizziness are increased among progestin-only oral contraceptive users in some studies.
- Androgenic side effects such as acne, hirsutism, and weight gain occur rarely.
DESCRIPTION
Each yellow DEBLITANE TM tablet provides a continuous oral contraceptive regimen of 0.35 mg norethindrone daily, and the inactive ingredients include polyvinyl alcohol, titanium dioxide, talc, macrogol/polyethylene glycol 3350 NF, D&C Yellow No. 10 Aluminum Lake, lecithin (soya), FD&C Red No. 40 Aluminum Lake, FD&C Blue No. 2 Aluminum Lake, lactose monohydrate, magnesium stearate, and pregelatinized starch.
The chemical name for norethindrone is 17-Hydroxy-19-Nor-17-alpha-pregn-4-en-20-yn-3-one. The structural formula follows:
Therapeutic class = Oral Contraceptive
CLINICAL PHARMACOLOGY
Mode of Action
DEBLITANE TM 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.
Pharmacokinetics
Absorption: Norethindrone is rapidly absorbed with maximum plasma concentrations occurring within 1 to 2 hours after DEBLITANE TM 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%.
Peak plasma concentrations occur approximately 1 hour after administration (mean T max 1.2 hours). The mean (SD) C max 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) C avg was 885 (250) pg/mL, however, the mean concentration at 24 hrs was 130 (47) pg/mL.
Table 1 provides summary statistics of the pharmacokinetic parameters associated with single dose Norethindrone Tablets administration.
The food effect on the rate and extent of norethindrone absorption after DEBLITANE TM administration has not been evaluated.
Distribution: Following oral administration, norethindrone is 36% bound to sex hormone-binding globulin (SHBG) and 61% bound to albumin. Volume of distribution of norethindrone is approximately 4 L/kg.
Metabolism: Norethindrone undergoes extensive biotransformation, primarily via reduction, followed by sulfate and glucuronide conjugation; less than 5% of a norethindrone dose is excreted unchanged; greater than 50% and 20 to 40% of a dose is excreted in urine and feces, respectively. The majority of metabolites in the circulation are sulfate, with glucuronides accounting for most of the urinary metabolites.
Excretion: Plasma clearance rate for norethindrone has been estimated to be approximately 600 L/day. Norethindrone is excreted in both urine and feces, primarily as metabolites. The mean terminal elimination half-life of norethindrone following single dose administration of Norethindrone Tablet is approximately 8 hours.
HOW SUPPLIED
DEBLITANE TM (Norethindrone Tablets, USP) contain 28 round yellow tablets in a blister card (NDC 16714-440-01). Each yellow tablet, debossed with “K2” on one side, contains 0.35 mg norethindrone.
DEBLITANE TM tablets are available in the following configurations:
Carton of 1 NDC 16714-440-02 Carton of 3 NDC 16714-440-03 Carton of 6 NDC 16714-440-04
STORAGE
Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature].
