Trade Names:Aygestin- Tablets 5 mgMicronor (Canada)
Inhibits secretion of pituitary gonadotropins, thereby preventing follicular maturation and ovulation.
Norethindrone acetate is rapidly absorbed from GI tract. T max is approximately 2 h.
Rapid distribution of dorethindrone acetate.
Norethindrone is metabolized in the liver.
Norethindrone elimination is rapid, primarily in feces.
Treatment of secondary amenorrhea; endometriosis; abnormal uterine bleeding caused by hormonal imbalance in the absence of organic pathology (eg, uterine cancer).
Thrombophlebitis, thrombolic disorders, cerebral apoplexy, or a history of these conditions; markedly impaired liver function or liver disease; known or suspected carcinoma of the breast; undiagnosed vaginal bleeding; missed abortion; as a diagnostic test for pregnancy.
PO 2.5 to 10 mg/day for 5 to 10 days during second half of the theoretical menstrual cycle.EndometriosisAdults
PO 5 mg/day initially for 2 wk, then increase in increments of 2.5 mg/day every 2 wk until 15 mg/day is achieved. Therapy may be continued at this level for 6 to 9 mo or until breakthrough bleeding demands temporary termination.
Store at controlled room temperature (59° to 86°F).
Elimination of norethindrone may be increased, decreasing the therapeutic effect.
Pregnanediol determinations may be altered; thyroid and LFT results may be affected; increased amounts of coagulation factors; reduced response to metyrapone test.
Thrombophlebitis; cerebral thrombosis and embolism; hypertension; edema.
Depression; changes in libido; changes in appetite; headache; nervousness; dizziness; fatigue.
Allergic rash; melasma; chloasma; hirsutism; alopecia; erythema multiforme; erythema nodosum; hemorrhagic eruption; itching.
Neuro-ocular lesions (eg, retinal thrombosis, optic neuritis).
Breakthrough bleeding; spotting; amenorrhea; increased cervical erosion and secretion; cystitis.
Weight gain and loss.
Premenstrual syndrome; backache.
Category X .
Excreted in breast milk.
Safety and efficacy not established.
Use with careful observation when conditions that might be affected by fluid retention are present (eg, asthma, cardiac or renal dysfunction, epilepsy).
Carefully observe patients with history of depression.
Discontinue therapy if there are any sudden changes in vision or onset of proptosis, diplopia, migraine, papilledema, or retinal vascular lesions.
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