Norethisterone, the active substance of Norethisterone tablets, belongs to the group of hormonal medicines called progestogen or progesteroids. As witth all progestogens, Norethisterone changes certain actions of oestrogens and it can be used in the treatment of menstrual disorders, in abnormal bleeding from the uterus because of hormonal imbalance
Norethisterone is indicated in menorrhagia, premenstrual syndrome and dysmenorrhea.
Hypersensitivity to the active substance or to any of the excipients of the product, pregnancy, hepatic insufficiency or hepatic disease, Dubin-Johnson or Rotor syndrome, history of idiopathic jaundice, severe pruritus, pemphigoid or herpes skin disorders during pregnancy and undiagnosed vaginal bleeding, history or current arterial disease, breast or genital tract carcinoma, unless Norethisterone is being used for the management of such conditions and porphyria.
A number of medicines interact with Norethisterone and should not be used concomitantly. However, a few of them can be used concomitantly under special precautions. In this case, your doctor can change the posology or take other precautions if needed.
If you are about to take Norethisterone, it is important to inform your doctor or pharmacist if you are taking any other medicines and particularly any of the following
Griseofulvin, aminoglutethimide, cyclosporine, anticoagulants, antiepileptics, rifamycin, antivirals, retinoids, wide spectrum antibacterials, analgesics, anticoagulants, antidepressants, antidiabetics, antihypertensives, benzodiazepines, clofibrate, corticosteroids, lignocaine, selegiline, thyroxine, xanthines, anticonvulsants (phenobarbital, phenytoin, carbamazepine), antiinfective (rifampicin, rifabutin, nevirapine, efavirenz, tetracyclines, ampicillin, oxacillin, cotrimoxazole), ritonavir, nelfinavir, herbal preparations containing St. John’s Wort (Hypericum perforatum), cytotoxic drugs, non-steroid anti-inflammatory drugs, vasodilators, terbinafine, barbiturates and amprenavir.
Hepatic function disturbance have been reported.
Administration of the drug should be interrupted in the following cases: Occurrence for the first time of migrainous headache or more frequent occurrence of unusually severe headaches, sudden perceptual disorder (e.g disturbances of vision or hearing), first signs of thrombophlebitis or thromboembolic syndrome, feeling of pain or tightness in the chest, significant rise in blood pressure, pregnancy, immobilization (e.g after accidents), onset of jaundice, hepatitis and pruritus, if you are to undergo surgery (administration of the drug should be interrupted six weeks beforehand)
Norethisterone is contraindicated during pregnancy.
Large doses of Noreth isterone may suspend lactation. Extra caution is necessary for its administration during lactation. Consult your doctor or pharmacists before taking any medicine
Driving and operation of machinery
Norethisterone is unlikely to influence the ability to drive and operate machinery.
Dosage and administration
Menorrhagia: 1 tablet 2-3 times daily from the 19th to the 26th day of the cycle (counting the first day of menstruation as day 1)
Premenstrual syndrome: 1 tablet 2-3 times daily from the 19th to the 26th day of the cycle. Treatment should be repeated for several cycles.
Dysmenorrhea: 1 tablet three times daily for 20 days, starting on the fifth day of the cycle (counting the first day of menstruation as day 1) for 3-4 cycles. Continuation of the therapy may be necessary if symptoms return.
Note: if menstrual bleeding should fail to follow a course of Norethisterone, the possibility of pregnancy must be ruled out before a further course is given.
In case you take a dose larger than normal contact your doctor immediately. Overdose symptoms include: nausea, vomiting and irregular bleeding during menstruation. Nausea and vomiting are treated by general supportive measures.
If you miss a dose, you should take the missed dose as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Possible undesirable effects
As with all medicines Norethisterone may cause undesirable effects. Most usual are: nausea, vomiting, acne, oedema, changes in appetite and body weight, fluid retention, melasma or chiloasma, allergic skin rashes and urticarial. Breakthrough bleeding especially when treatment is prolonged. Breast changes, including discomfort, headache and depression, changes in libido, hair loss, fatigue, drowsiness or insomnia, fever, pre-menstrual syndrome like symptoms. Androgenic effects with deepening of the voice and hirsutism and oestrogenic effects have been reported after prolonged therapy.
Anaphylaxis or anaphylactoid reactions may occur rarely. Alterations in liver function have been reported and jaundice has been reported rarely. Virilisation of female foetus have been reported. Exacerbation of epilepsy and migraine reduced tolerance to contact lenses and deterioration in vision in patients who already have problematic vision have been reported.
If you experience undesirable effects that are not mentioned above, please inform your doctor.