Antah Pharma
Full Prescribing Info
Each tablet contains: Norethisterone 5 mg.
Pharmacology: Norethisterone has pharmacological properties similar to progesterone.
Norethisterone is absorbed from the gastrointestinal tract and its effect last for at least 24 hours. When injected, it is detectable in the plasma after 2 days and is not completely excreted in the urine after 5 days.
Norethisterone has progestational actions similar to those of progesterone. It acts on the endometrium by converting the proliferative phase induced by oestrogen to a secretory phase. It inhibits the secretion of pituitary gonadotropins, which in turn presents follicular maturation and ovulation. Norethisterone is a more potent inhibitor of ovulation to progesterone and in addition it has weak oestrogenic and androgenic properties.
It is indicated in amenorrhea, in abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology, such as submucous fibroids or uterine cancer, and in endometriosis.
Dosage/Direction for Use
Therapy with norethisterone must be adapted to the specific indications and therapeutic response of the individual patient. This dosage schedule assumes the interval between menses to be 28 days.
Amenorrhea, abnormal uterine bleeding due to hormonal imbalance in the absence of organic pathology: 5 to 20 mg norethisterone starting with the fifth day of the menstrual cycle and ending on the 25th day.
Endometriosis: Initial daily dosage of 10mg for two weeks with increments of 5 mg per day every two weeks until 30 mg per day is reached. Therapy may be held at this level for six to nine months or until breakthrough bleeding demands temporary termination.
Symptoms of overdosage include nausea, vomiting, breast enlargement and vaginal bleeding. There is no specific antidote and treatment should be symptomatic. Gastric lavage may be employed if the overdosage is large and the patient is seen sufficiently early (within 4 hours).
Thrombophlebitis, thromboembolic disorders, cerebral apoplexy or patients with a past history of these conditions; Known or suspected carcinoma of the breast; Undiagnosed vaginal bleeding; Missed abortion; As a diagnostic test for pregnancy.
Special Precautions
Because of occasional occurrence of thrombophlebitis and pulmonary embolism in patients taking progestogens, the physician should be alerted to the earliest manifestations of the disease. This drug may cause some degree of fluid retention, conditions which might be influenced by this factor, such as epilepsy, migraine, asthma, cardiac or renal dysfunction, require careful observation.
In cases of breakthrough bleeding, as in all cases of irregular bleeding per vaginam, non- functional causes should be borne in mind. In cases of undiagnosed vaginal bleeding, adequate diagnostic measures are indicated.
A decrease in glucose tolerance has been observed in a small percentage of patients on oestrogen-progestogen combination drugs. The mechanism of this decrease is obscure.
For this reason, diabetic patients should be carefully observed while receiving progestogen therapy. Steroid hormones are metabolized by the liver, therefore, these drugs should be administered with caution in patients with impaired liver function.
Use In Pregnancy & Lactation
The use of norethisterone during the first four months of pregnancy is not recommended.
Norethisterone given in the postpartum period may interfere with lactation by decreasing the quantity and quality of breast milk. Detectable amounts of progesterone appears in the milk and their effect on the breastfed child has not been determined.
Adverse Reactions
Breakthrough bleeding; Spotting; Change in menstrual flow; Amenorrhea; Oedema; Changes in weight; Changes in cervical mucous and cervical secretion; Cholestatic jaundice; Rash (allergic) with and without pruritus; Melasma or chloasma; Mental depression; Nausea; Headache; Visual disturbances.
Drug Interactions
The concomitant use of oestrogens with progestogens may rendered less effective and an increased incidence of breakthrough bleeding may occur by virtue of drug interaction with rifampicin, isoniazid, ampicillin, tetracycline, neomycin, penicillin, chloramphenicol, sulphonamides, nitrofurantoin, barbiturates, phenytoin, primidone, analgesics, tranquilisers, antimigraine preparations and antihistamines. They may also alter the effectiveness of drugs such as oral anticoagulants, anti-convulsants, tricyclic anti-depressants, anti-hypertensive agents (e.g. guanethidine), vitamins, hypoglycaemic agents, tranquilisers, hypnotic preparations and theophylline.
Store at temperature 25°C.
Shelf-Life: 4 years.
MIMS Class
Oestrogens, Progesterones & Related Synthetic Drugs
ATC Classification
G03DC02 - norethisterone ; Belongs to the class of estren derivative progestogens used in progestogenic hormone preparations.
Tab 5 mg (round, white, convex, plain with single score on one side and "SW' debossed on the other side) x 5 x 10 x 10's.
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