VAGIFEM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VAGIFEM (VAGIFEM).
Estradiol is a form of estrogen that binds to estrogen receptors, activating gene transcription and leading to various physiological effects. It replaces endogenous estrogen in postmenopausal women, alleviating symptoms of vaginal atrophy.
| Metabolism | Primarily hepatic via CYP3A4. Undergoes extensive first-pass metabolism when administered orally; however, vaginal administration reduces first-pass effect. |
| Excretion | Vagifem (estradiol) undergoes hepatic metabolism and renal excretion. Approximately 60-80% of a dose is excreted in urine as glucuronide and sulfate conjugates, with about 10-15% excreted in feces via biliary elimination. Unchanged estradiol is minimally excreted. |
| Half-life | The terminal elimination half-life of estradiol is approximately 2-3 hours. Due to enterohepatic recirculation, the effective half-life may be longer, and daily dosing maintains steady-state concentrations. |
| Protein binding | Estradiol is approximately 98% bound to sex hormone-binding globulin (SHBG) and albumin, with SHBG binding being of higher affinity. |
| Volume of Distribution | The volume of distribution for estradiol is approximately 1 L/kg (range 0.5-1.5 L/kg), indicating extensive distribution into tissues, particularly fat and reproductive organs. |
| Bioavailability | Vagifem has a bioavailability of approximately 5-10% via vaginal route due to first-pass hepatic metabolism. Oral bioavailability is less than 5%, but not relevant for this product. |
| Onset of Action | The onset of action for Vagifem (estradiol vaginal tablet) is 2-4 weeks for improvement in vaginal symptoms (e.g., dryness, dyspareunia). Systemic effects, if any, occur more slowly. |
| Duration of Action | Duration of action for Vagifem is 24 hours after each dose, but given the local delivery, clinical effects persist with regular use. Symptoms may recur within a few days to weeks after discontinuation. |
| Molecular Weight | 272.38 Da |
One vaginal tablet (10 mcg estradiol) inserted daily for 2 weeks, then maintenance of one tablet twice weekly.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | Contraindicated in severe hepatic disease (Child-Pugh class C). Use with caution in mild to moderate impairment (Child-Pugh A or B) with monitoring; specific dose reductions not defined. |
| Pediatric use | Not indicated for use in pediatric patients (safety and efficacy not established). |
| Geriatric use | Use lowest effective dose; monitor for endometrial hyperplasia/bleeding and thromboembolic risk. No specific dose reduction required. |
| 1st trimester | Contraindicated due to risk of urogenital abnormalities in female fetuses and potential feminization of male fetuses. |
| 2nd trimester | Contraindicated; data indicate increased risk of spontaneous abortion and stillbirth. |
| 3rd trimester | Contraindicated; may cause adverse effects such as preterm birth and low birth weight. |
Clinical note
Comprehensive clinical and safety monograph for VAGIFEM (VAGIFEM).
| Placental transfer | Estradiol readily crosses the placenta; data from transdermal and oral estradiol show fetal levels approximately 25% of maternal levels. |
| Breastfeeding | Excreted in human milk in small amounts; in a 2-month old infant exposed to Vagifem, estradiol levels were comparable to endogenous infant levels. Consider the need for therapy and potential effects on milk production (may decrease) and infant development. |
■ FDA Black Box Warning
Estrogen-alone therapy increases the risk of endometrial cancer. Estrogen plus progestin therapy increases the risk of breast cancer, stroke, and deep vein thrombosis.
| Serious Effects |
Undiagnosed abnormal genital bleedingKnown, suspected, or history of breast cancerKnown or suspected estrogen-dependent neoplasiaActive thromboembolic disorders (e.g., DVT, PE) or history of these conditionsPregnancy or suspected pregnancy
| Precautions | Cardiovascular disorders: Increased risk of stroke and DVT, Malignant neoplasms: Endometrial cancer, breast cancer, Gallbladder disease, Hypercalcemia in patients with bone metastases, Hereditary angioedema, Visual abnormalities (e.g., retinal vascular thrombosis), Exacerbation of endometriosis |
| Food/Dietary | None known. |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category X. First trimester: Increased risk of genital tract abnormalities in female offspring (e.g., vaginal adenosis, cervical erosion, clear cell adenocarcinoma). Second and third trimesters: Possible increased risk of urogenital anomalies and later reproductive dysfunction; use is contraindicated throughout pregnancy. |
| Fetal Monitoring | Monitor fetal growth and amniotic fluid volume; assess for signs of estrogenic effects (e.g., vaginal bleeding, uterine enlargement). Check maternal blood pressure, liver function, and thyroid function periodically. |
| Fertility Effects | May mask or alter menstrual cycle; potential for reduced fertility due to suppression of ovulation. Use in fertility treatment is limited to specific protocols under specialist guidance. |
| Clinical Pearls | Vagifem (estradiol vaginal insert) is indicated for the treatment of atrophic vaginitis due to menopause. Use the lowest effective dose for the shortest duration. Insert one tablet vaginally daily for 2 weeks, then twice weekly. Monitor for endometrial hyperplasia if used longer than 6 months. Avoid in patients with known or suspected breast cancer, estrogen-dependent neoplasia, undiagnosed abnormal genital bleeding, active thromboembolic disorders, or pregnancy. |
| Patient Advice | Insert one tablet vaginally at bedtime daily for the first 2 weeks, then reduce to twice weekly (e.g., Monday and Thursday). · Wash hands before and after insertion. Use the provided applicator or insert with fingers. Lie down for 10 minutes after insertion to prevent expulsion. · Do not use as a contraceptive; it does not protect against sexually transmitted infections. · Report any abnormal vaginal bleeding, breast lumps, pain in the legs or chest, sudden shortness of breath, or vision changes immediately. · Avoid using other vaginal products (e.g., douches, lubricants) within 1 hour of insertion. |