GILDESS FE 1.5/30
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GILDESS FE 1.5/30 (GILDESS FE 1.5/30).
Combination oral contraceptive: ethinyl estradiol (estrogen) and levonorgestrel (progestin) suppress gonadotropin secretion (FSH and LH) via negative feedback, inhibiting ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.
| Metabolism | Ethinyl estradiol: primarily metabolized by CYP3A4; undergoes conjugation (glucuronidation and sulfation). Levonorgestrel: metabolized by reduction and conjugation; CYP3A4 involved. |
| Excretion | Ethinyl estradiol (EE) is primarily excreted in urine (40-45%) and feces (40-45%) as glucuronide and sulfate conjugates; less than 8% is excreted unchanged. Gestodene is extensively metabolized; its metabolites are excreted in urine (50-60%) and feces (30-40%), with less than 1% unchanged. |
| Half-life | Ethinyl estradiol: terminal elimination half-life approximately 13-27 hours (mean ~17 hours); clinical context: supports daily dosing with steady state achieved in ~1 week. Gestodene: terminal elimination half-life approximately 12-15 hours; clinical context: allows for maintaining stable serum concentrations with once-daily dosing. |
| Protein binding | Ethinyl estradiol: 97-98% bound to albumin; gestodene: 65-75% bound to sex hormone-binding globulin (SHBG) and 25-35% bound to albumin; total binding ~99%. |
| Volume of Distribution | Ethinyl estradiol: apparent Vd ~2.5-4.0 L/kg (mean ~3 L/kg); indicates extensive tissue distribution beyond plasma volume. Gestodene: apparent Vd ~0.7-1.0 L/kg; suggests moderate distribution to tissues. |
| Bioavailability | Ethinyl estradiol: oral bioavailability approximately 40-45% due to first-pass metabolism (sulfation and glucuronidation in gut wall and liver); interindividual variability significant. Gestodene: oral bioavailability nearly 100% (99-100%) due to minimal first-pass metabolism; high and consistent absorption. |
| Onset of Action | Oral administration: contraceptive effect (ovulation inhibition) occurs after 7 days of consistent dosing when initiated on day 1 of menstrual cycle; if started later, backup contraception needed for 7 days. |
| Duration of Action | Contraceptive effect persists for 24 hours with daily dosing; after discontinuing, ovulation returns within 1-2 weeks in most women, though some may experience delay. |
One tablet orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal impairment (eGFR <30 mL/min/1.73 m²) due to potential estrogen-related fluid retention and hypertension. |
| Liver impairment | Contraindicated in Child-Pugh class B and C (moderate to severe hepatic impairment). Use with caution in Child-Pugh class A; closely monitor liver function. |
| Pediatric use | Not indicated for use before menarche. Post-menarche: same as adult dosing; one tablet orally once daily. |
| Geriatric use | Not indicated for use in postmenopausal women due to lack of efficacy for contraception and potential increased thromboembolic risk. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GILDESS FE 1.5/30 (GILDESS FE 1.5/30).
| Breastfeeding | Contraindicated in breastfeeding. Estrogen and progestin components reduce milk production and quality. Limited data; M/P ratio not established. Alternative contraception recommended. |
| Teratogenic Risk | Pregnancy category X. Use contraindicated in pregnancy due to estrogenic effects on fetal development. First trimester: increased risk of congenital anomalies (cardiovascular, limb defects). Second and third trimesters: potential for fetal harm, including jaundice and liver dysfunction. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age (especially >35 years) and number of cigarettes smoked. Women >35 years who smoke should not use this product.
| Serious Effects |
["Thrombophlebitis or thromboembolic disorders","Cerebrovascular or coronary artery disease","Known or suspected breast cancer","Estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Pregnancy","Benign or malignant liver tumor","Hepatic impairment","Hypersensitivity to components","Women >35 years who smoke"]
| Precautions | ["Thrombotic disorders (venous thromboembolism, arterial thromboembolism, stroke, myocardial infarction)","Carcinoma of the breast and reproductive organs","Hepatic neoplasia","Gallbladder disease","Carbohydrate and lipid metabolism effects","Elevated blood pressure","Headache","Bleeding irregularities","Ocular lesions (e.g., retinal thrombosis)","Depression"] |
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| Fetal Monitoring |
| Pregnancy test prior to initiation. Monitor for symptoms of thromboembolism, hypertension, liver dysfunction. No routine fetal monitoring required if contraindication observed. |
| Fertility Effects | Reversible suppression of ovulation. No long-term impact on fertility after discontinuation. May cause transient menstrual irregularities post-use. |