What Is Estrostep?
Estrostep 21 (norethindrone acetate and ethinyl estradiol) is an oral contraceptive that contains a combination of female hormones used to prevent pregnancy. Estrostep 21 is also used to treat severe acne. Estrostep 21 may be available in generic form.
What Are Side Effects of Estrostep?
Common side effects of Estrostep 21 include:
- stomach cramping/bloating,
- vaginal discomfort/irritation,
- increased vaginal fluids, or
- breast tenderness/enlargement
Acne may improve or get worse. Other side effects of Estrostep 21 include:
- vaginal bleeding between periods (spotting)
- missed/irregular periods, especially during the first few months of use
Dosage for Estrostep
The dose of Estrostep 21 is 1 tablet taken daily for 21 consecutive days. Wait 7 days to start the next pack. You will probably have your period during that week. Be sure that no more than 7 days pass between 21-day packs.
What Drugs, Substances, or Supplements Interact with Estrostep?
Estrostep 21 may interact with acetaminophen, ascorbic acid (vitamin C), prednisolone, theophylline, St. John's wort, antibiotics, seizure medications, barbiturates, or HIV or AIDS medications. Tell your doctor all medications and supplements you use. Estrostep 21 must not be used during pregnancy.
Estrostep During Pregnancy or Breastfeeding
If you have just given birth or had a pregnancy loss/abortion after the first 3 months, consult your doctor and find out when it is safe to use birth control containing estrogen. Estrostep 21 passes into breast milk. Consult your doctor before breastfeeding.
Our Estrostep 21 (norethindrone acetate and ethinyl estradiol) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
An increased risk of the following serious adverse reactions has been associated with the use of combined oral contraceptives (see WARNINGS section):
- Arterial thromboembolism
- Pulmonary embolism
- Myocardial infarction
- Cerebral hemorrhage
- Cerebral thrombosis
- Gallbladder disease
- Hepatic adenomas or benign liver tumors
There is evidence of an association between the following conditions and the use of combined oral contraceptives, although additional confirmatory studies are needed:
- Mesenteric thrombosis
- Retinal thrombosis
The following adverse reactions have been reported in patients receiving combined oral contraceptives and are believed to be drug-related:
- Gastrointestinal symptoms (such as abdominal cramps and bloating)
- Breakthrough bleeding
- Change in menstrual flow
- Temporary infertility after discontinuation of treatment
- Melasma which may persist
- Breast changes: tenderness, enlargement, secretion
- Change in weight (increase or decrease)
- Change in cervical erosion and secretion
- Diminution in lactation when given immediately postpartum
- Cholestatic jaundice
- Rash (allergic)
- Mental depression
- Mood swings
- Reduced tolerance to carbohydrates
- Vaginal candidiasis
- Change in corneal curvature (steepening)
- Intolerance to contact lenses
The following adverse reactions have been reported in users of combined oral contraceptives and the association has been neither confirmed nor refuted:
- Pre-menstrual syndrome
- Changes in appetite
- Cystitis-like syndrome
- Loss of scalp hair
- Erythema multiforme
- Erythema nodosum
- Hemorrhagic eruption
- Impaired renal function
- Hemolytic uremic syndrome
- Budd-Chiari syndrome
- Changes in libido
Effects Of Other Drugs On Combined Oral Contraceptives
Metabolism of both norethindrone and ethinyl estradiol is increased by rifampin. A reduction in contraceptive effectiveness and increased incidence of breakthrough bleeding and menstrual irregularities have been associated with concomitant use of rifampin.
Anticonvulsants such as phenobarbital, phenytoin, and carbamazepine, have been shown to increase the metabolism of ethinyl estradiol and/or norethindrone, which could result in a reduction in contraceptive effectiveness.
Pregnancy while taking combined oral contraceptives has been reported when the combined oral contraceptives were administered with antimicrobials such as ampicillin, tetracycline, and griseofulvin. However, clinical pharmacokinetic studies have not demonstrated any consistent effect of antibiotics (other than rifampin) on plasma concentrations of synthetic steroids.
Coadministration of atorvastatin and an combined oral contraceptive increased AUC values for norethindrone and ethinyl estradiol by approximately 30% and 20%, respectively.
St. John’s Wort
Herbal products containing St. John’s Wort (hypericum perforatum) may induce hepatic enzymes (cytochrome P450) and p-glycoprotein transporter and may reduce the effectiveness of combined oral contraceptives. This may also result in breakthrough bleeding.
Human Immunodeficiency Virus (HIV)/Hepatitis C Virus (HCV) Protease Inhibitors And Nonnucleoside Reverse Transcriptase Inhibitors
Significant changes (increase or decrease) in the plasma concentrations of estrogen and progestin have been noted in some cases of co-administration with HIV/HCV protease inhibitors (decrease [e.g., nelfinavir, ritonavir, darunavir/ritonavir, (fos)amprenavir/ritonavir, lopinavir/ritonavir, and tipranavir/ritonavir] or increase [e.g., indinavir and atazanavir/ritonavir])/HCV protease inhibitors (decrease [e.g., boceprevir and telaprevir]) or with non-nucleoside reverse transcriptase inhibitors (decrease [e.g., nevirapine] or increase [e.g., etravirine]).
Concomitant Use With HCV Combination Therapy – Liver Enzyme Elevation
Do not co-administer ESTROSTEP Fe with HCV drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, due to potential for ALT elevations (see WARNINGS, RISK OF LIVER ENZYME ELEVATIONS WITH CONCOMITANT HEPATITIS C TREATMENT).
Ascorbic acid and acetaminophen may increase plasma ethinyl estradiol concentrations, possibly by inhibition of conjugation. A reduction in contraceptive effectiveness and increased incidence of breakthrough bleeding has been suggested with phenylbutazone.
Effects Of Combined Oral Contraceptives On Other Drugs
COCs containing ethinyl estradiol may inhibit the metabolism of other compounds (e.g., cyclosporine, prednisolone, theophylline, tizanidine, and voriconazole) and increase their plasma concentrations. COCs have been shown to decrease plasma concentrations of acetaminophen, clofibric acid, morphine, salicylic acid, temazepam and lamotrigine. Significant decrease in plasma concentration of lamotrigine has been shown, likely due to induction of lamotrigine glucuronidation. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary.
Women on thyroid hormone replacement therapy may need increased doses of thyroid hormone because the serum concentration of thyroid-binding globulin increase with use of COCs.
Read the entire FDA prescribing information for Estrostep (Norethindrone Acetate and Ethinyl Estradiol)
© Estrostep Patient Information is supplied by Cerner Multum, Inc. and Estrostep Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.
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