estring
Pharmaranks rates Estring 3.2/5 for recall safety — an independent score from its FDA recall history and its manufacturer's record. Estring (Estradiol) is an estrogen used to treat Breast Neoplasms, Hypogonadism, Premature Menopause, Menorrhagia.
Estradiol · by Pfizer
Available as a generic: Estradiol
Based on 1 source · Recall-safety score from FDA recall history — this product's own recalls and its manufacturer's record. Not an efficacy or quality rating. methodology →
Key facts
- Active ingredient
- Estradiol
- Drug class
- Estrogen
- Form
- System
- Strength
- Estradiol 0.0075MG/24HR
- Type
- Prescription (Rx)
- Brand or generic
- Brand-name
- May treat
- breast neoplasms, hypogonadism, premature menopause
- Manufacturer
- Pfizer
- What the pharmacy pays
- ~$6.55 per gm — not your price
- FDA application
- NDA020472
What is Estring?
From the FDA label:ESTRING ® (estradiol vaginal system) is a slightly opaque ring with a whitish core containing a drug reservoir of 2 mg estradiol. Estradiol, silicone polymers, barium sulfate and silicone fluid (as dispersing agent) are combined to form the ring. When placed in the vagina, ESTRING releases estradiol, approximately 7.5 mcg per day, in a consistent stable manner over 90 days. ESTRING has the following dimensions: outer diameter 55 mm; cross-sectional diameter 9 mm; core diameter 2 mm. One ESTRING should be inserted into the upper third of the vaginal vault, to be worn continuously for three months. Estradiol is chemically described as estra-1, 3, 5(10)-triene-3, 17β-diol. The molecular formula of estradiol is C 18 H 24 O 2 and the structural formula is: The molecular weight of estradiol is 272.39. Chemical Structure
How to use
One ESTRING (estradiol vaginal system) is to be inserted as deeply as possible into the upper one-third of the vaginal vault. The ring is to remain in place continuously for three months, after which it is to be removed and, if appropriate, replaced by a new ring. Should the ring be removed or fall out at any time during the 90-day treatment period, the ring should be rinsed in lukewarm water and re-inserted by the patient, or, if necessary, by a physician or nurse. Retention of the ring for greater than 90 days does not represent overdosage but will result in progressively greater underdosage with the attendant risk of loss of efficacy and increasing risk of vaginal infections and/or erosions. Instructions for Use ESTRING (estradiol vaginal system) insertion The ring should be pressed into an oval and inserted into the upper third of the vaginal vault. The exact position is not critical. When ESTRING is in place, the patient should not feel anything. If the patient feels discomfort, ESTRING is probably not far enough inside. Gently push ESTRING further into the vagina. ESTRING use ESTRING should be left in place continuously for 90 days and then, if continuation of therapy is deemed appropriate, replaced by a new ESTRING. The patient should not feel ESTRING when it is in place and it should not interfere with sexual intercourse. Straining at defecation may make ESTRING move…
Side effects
See WARNINGS and PRECAUTIONS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the two ESTRING controlled studies, discontinuation of treatment due to an adverse event was required by 5.4 percent of patients receiving ESTRING and 3.9 percent of patients receiving conjugated estrogens vaginal cream. The most common reasons for withdrawal from ESTRING treatment due to an adverse event were vaginal discomfort and gastrointestinal symptoms. The adverse events reported with a frequency of 3 percent or greater in the two pivotal controlled studies by patients receiving ESTRING or conjugated estrogens vaginal cream are listed in Table 3. TABLE 3: Adverse Events Reported by 3 Percent or More of Patients Receiving Either ESTRING or Conjugated Estrogens Vaginal Cream in Two Pivotal Controlled Studies ADVERSE EVENT ESTRING (n = 257) % Conjugated Estrogens Vaginal Cream (n = 129) % Musculoskeletal Back Pain 6 8 Arthritis 4 2 Arthralgia 3 5 Skeletal Pain 2 4 CNS/Peripheral Nervous System Headache 13 16 Psychiatric Insomnia 4 0 Gastrointestinal Abdominal Pain 4 2 Nausea 3 2 Respiratory Upper Respiratory Tract Infection 5 6 Sinusitis 4 3 Pharyngitis 1 3 Urinary Urinary Tract…
Warnings
Important safety information
1. Endometrial Cancer with Unopposed Estrogen in Women with a Uterus In ESTRING-treated menopausal women with a uterus with persistent or recurring abnormal genital bleeding of unknown etiology, perform adequate diagnostic measures, including directed or random endometrial sampling when indicated, to assess for endometrial cancer. There is an increased risk of endometrial cancer with the use of systemic estrogens alone in women with a uterus. The reported endometrial cancer risk among unopposed systemic estrogen users is about 2 to 12 times greater than in non-users and appears dependent on duration of treatment and on estrogen dose. Most studies show no significant increased risk associated with the use of systemically administered estrogens for less than one year. The greatest risk appears to be associated with prolonged use, with increased risks of 15- to 24-fold for 5 to 10 years or more. This risk has been shown to persist for at least 8 to 15 years after systemic estrogen therapy is discontinued. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent estrogen dose. Adding a progestogen to estrogen-alone therapy has been shown to reduce the risk of endometrial hyperplasia (possible precursor to endometrial cancer). There is, however, a different risk profile associated with the use of progestogens plus estrogens compared to estrogen-alone regimens. 2. Risks Associated with Concomitant Use of Estrogen Plus Progestogen If ESTRING is administered with a progestogen, there are possible risks associated with the concomitant use of estrogen with progestogen that differ from those of estrogen-alone regimens. Refer to the prescribing information for progestogens indicated for the prevention of endometrial hyperplasia in nonhysterectomized women receiving estrogens for a discussion of the risks of estrogen and progestogen concomitant therapy. 3. Risks with Systemic Estrogen-Alone Therapy Systemic absorption occurs with the use of ESTRING, although the exposure is generally lower than that of systemic estrogens indicated for vasomotor symptoms. As such, the relevance or extent of the following risks of systemic estrogens to ESTRING is not known. The following adverse reactions have been reported with systemic estrogen therapy: Cardiovascular diseases: The Women’s Health Initiative (WHI) estrogen-alone trial reported increased risks of pulmonary embolism (PE), deep vein thrombosis (DVT), and stroke, in postmenopausal women (50 to 79 years of age, average age 63.4 years) during 7.2 years of treatment with daily oral conjugated estrogens (CE) [0.625 mg] relative to placebo. (See CLINICAL STUDIES .) Breast cancer: In the WHI estrogen-alone trial, after an average follow-up of 7.1 years, daily oral CE-alone was not associated with an increased risk of invasive breast cancer. (See CLINICAL STUDIES .) However, a large meta-analysis including 24 prospective studies of postmenopausal women comparing current use of estrogen-only products with use duration of 5 to 14 years (average of 9 years) versus never use reported a relative risk for breast cancer of 1.33 (95% CI, 1.28 to 1.38). Ovarian cancer: A large meta-analysis including 17 prospective studies of postmenopausal women compared current use of estrogen-only products versus never user and reported a relative risk for ovarian cancer of 1.37 (95% CI 1.26, 1.50). The duration of hormone therapy use that was associated with an increased risk of ovarian cancer is unknown. 4 Others: gallbladder disease requiring surgery, severe hypercalcemia in women with breast cancer and metastases, retinal vascular thrombosis, substantial increases in blood pressure from idiosyncratic reactions, exacerbation of hypertriglyceridemia leading to pancreatitis, cholestatic jaundice, exacerbation of hypothyroidism, fluid retention, hypocalcemia, exacerbation of conditions including hereditary angioedema, asthma, diabetes mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and hepatic hemangiomas.
Who should not take Estring
ESTRING is contraindicated in women with any of the following conditions: 1. Abnormal genital bleeding with unknown etiology. 2. Known or suspected estrogen-dependent neoplasia. 3. Active DVT, PE, or a history of these conditions. 4. Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions. 5. Known anaphylactic reaction or angioedema or hypersensitivity to ESTRING. 6. Known liver impairment or disease. 7. Protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders.
Overdose — what happens if you take too much
Overdosage of estrogen may cause nausea, vomiting, breast tenderness, abdominal pain, drowsiness and fatigue, and withdrawal bleeding may occur in women. Treatment of overdose consists of discontinuation of ESTRING together with institution of appropriate symptomatic care.
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Drug class
How this class works, per Estrogen - StatPearls - NCBI Bookshelf.
May treat (source: NIH RxClass)
- breast neoplasms
- hypogonadism
- premature menopause
- menorrhagia
- prostatic neoplasms
- primary ovarian insufficiency
See how Estring ranks — best-rated estrogen for:
Dosage forms
System
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
Ways to save
Ask for the generic
Same active ingredient, far cheaper. Is there a generic? →
Request a 90-day supply
Bulk fills usually lower the per-dose price vs monthly refills.
Use copay cards
Manufacturer copay cards & patient-assistance programs — especially for brand drugs.
Compare alternatives
A same-class option may cost less. See alternatives →
Frequently asked questions
- What does Estring treat?
- Estring (Estradiol) may be used to treat breast neoplasms, hypogonadism, premature menopause, menorrhagia, prostatic neoplasms, primary ovarian insufficiency, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- How does Estring work?
- Estring is a estrogen. Estrogen is a sex hormone that enters cells and binds estrogen receptors; the hormone-receptor complex then moves into the nucleus and switches target genes on or off. Through this it thickens the uterine lining, helps protect bone, supports breast and vaginal tissue, and shapes cholesterol levels.
- How is Estring rated?
- pharmaranks gives Estring a composite score of 3.2 out of 5, currently based on 1 weighted source (FDA regulatory recall-safety data weighted highest). See our methodology at /how-we-rate.
- How much does Estring cost?
- Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $6.55 per gm, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins.
- Is there a coupon or discount for Estring?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Estring. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Estring?
- Estring is marketed by Pfizer. You can see Pfizer's full profile, rating, and other products on pharmaranks.
- Is Estring a brand-name or generic drug?
- Estring is a brand-name product with the active ingredient Estradiol. Lower-cost generic equivalents containing Estradiol are available — ask your pharmacist.
- Is Estring available over the counter?
- No. Estring is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Estring come in?
- Estring is currently marketed as system, per the FDA's National Drug Code Directory.
- What class of drug is Estring?
- Estring is classified as estrogen, per the FDA's Established Pharmacologic Class.
- Is Estring FDA-registered?
- Estring is on record with the U.S. FDA under application number NDA020472. You can verify this on its official FDA label.
- Has Estring been recalled by the FDA?
- Estring has no FDA recalls recorded under its own application in the openFDA enforcement database. Its recall-safety score reflects its manufacturer's overall recall record. This is general reference, not medical advice — check the FDA recall database for the latest alerts.
- Is Estring safe?
- There's no single safe-or-not verdict. pharmaranks gives Estring a recall-safety score of 64/100, based on its FDA recall history (no recalls under its own FDA application) — not an efficacy or side-effect rating. Review its FDA-label side effects and warnings before use, and always consult a licensed professional.
- What are the side effects of Estring?
- Estring's side effects are taken directly from its FDA label. From the label: See WARNINGS and PRECAUTIONS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
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estring
64/100