GILDESS 1.5/30
Clinical safety rating
cautionComprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).
Combination of estrogen (ethinyl estradiol) and progestin (desogestrel) that inhibits gonadotropin release, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial morphology.
| Metabolism | Ethinyl estradiol undergoes first-pass metabolism in gut wall and liver via CYP3A4; desogestrel is metabolized by CYP2C9 and CYP2C19 to active metabolite etonogestrel. |
| Excretion | Renal: ~55-60% as ethinylestradiol glucuronide and sulfate conjugates; ~40% as desogestrel metabolites (largely as 3-keto-desogestrel glucuronide). Fecal: ~30-35% of desogestrel metabolites; <5% for ethinylestradiol. Biliary: minor for both. |
| Half-life | Ethinylestradiol: terminal half-life 13-17 hours (mean 15 h). Desogestrel active metabolite 3-keto-desogestrel: terminal half-life 23-28 hours (mean 25 h). Clinical: steady-state achieved by cycle day 7-10; missed pill instructions based on half-life. |
| Protein binding | Ethinylestradiol: ~97% bound to albumin (90%) and SHBG (minor). 3-Keto-desogestrel: ~95% bound: albumin (65%) and SHBG (30%). |
| Volume of Distribution | Ethinylestradiol: Vd ~2.5-3.0 L/kg; distributes extensively into body tissues (breast, liver). 3-Keto-desogestrel: Vd ~1.5-2.0 L/kg; moderate tissue binding. |
| Bioavailability | Oral: ethinylestradiol ~40-50% (due to first-pass metabolism); desogestrel ~76% (≥60% converted to active 3-keto-desogestrel after first pass). |
| Onset of Action | Oral: contraceptive effect requires 7 days of continuous dosing to suppress ovulation. Maximal plasma concentrations: ethinylestradiol 1.5-2 h; 3-keto-desogestrel 1-2 h. |
| Duration of Action | Oral: contraceptive protection persists for the 21-day active pill period; 7-day placebo interval allows withdrawal bleed. Full ovulation suppression maintained with consistent daily dosing. |
| Molecular Weight | Ethinylestradiol: 296.4 Da; Gestodene: 310.4 Da. |
| Action Class | Oral Contraceptive; Estrogen-Progestin Combination |
One tablet orally once daily at the same time each day.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in patients with renal impairment (eGFR <60 mL/min/1.73 m2) due to increased risk of hyperkalemia and reduced efficacy. |
| Liver impairment | Contraindicated in patients with hepatic impairment (Child-Pugh class B or C) due to impaired hormone metabolism and potential for adverse effects. |
| Pediatric use | Not indicated for use in pediatric patients. Safety and efficacy have not been established in females under 18 years of age. |
| Geriatric use | Not indicated for use in postmenopausal women. Efficacy in women over 40 years of age has not been fully established; consider alternative contraception due to increased cardiovascular risk. |
| 1st trimester | Contraindicated in pregnancy; risk of fetal cardiovascular and neural tube defects. |
| 2nd trimester | Contraindicated in pregnancy; risk of fetal cardiovascular and neural tube defects. |
| 3rd trimester | Contraindicated in pregnancy; risk of fetal cardiovascular and neural tube defects. |
Clinical note
Comprehensive clinical and safety monograph for GILDESS 1.5/30 (GILDESS 1.5/30).
| Placental transfer | Yes, ethinylestradiol and gestodene cross the placenta with measurable fetal concentrations. |
| Breastfeeding | Excreted in human milk; may cause adverse effects in nursing infants. Use with caution, especially during first month postpartum. |
| Lactation Rating | L3 (Moderately Safe) per Hale's classification. |
| Teratogenic Risk | First trimester: Combination oral contraceptives are not associated with a major increase in risk of birth defects. Second and third trimesters: Prolonged use may be associated with fetal harm including cardiovascular and skeletal anomalies, though data are limited. Known pregnancy contraindicates use. |
| Fetal Monitoring | Monitor liver function, blood pressure, and glucose tolerance. No specific fetal monitoring required, but pregnancy should be ruled out before initiating therapy. |
| Fertility Effects | No long-term impairment of fertility. Normal fertility returns upon discontinuation. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age and smoking intensity (especially in women over 35).
| Common Effects | Nausea, Headache, Breast tenderness, Weight changes, Irregular uterine bleeding, Mood changes, Acne |
| Serious Effects | Venous thromboembolism (VTE), Arterial thromboembolism (e.g., stroke, myocardial infarction), Hepatic adenoma or hepatocellular carcinoma, Hypertension, Gallbladder disease, Thrombotic thrombocytopenic purpura (TTP), Hemolytic uremic syndrome (HUS) |
PregnancyHistory of venous thromboembolismActive liver diseaseKnown thrombophiliaCarcinoma of the breast or reproductive organsUndiagnosed abnormal uterine bleedingHeadache with focal neurological symptoms or migraine with aura over age 35Smoking over age 35Uncontrolled hypertension
| Precautions | Increased risk of thromboembolic disorders (e.g., DVT, PE), Myocardial infarction and stroke risk, Hepatic neoplasia, Gallbladder disease, Hypertension, Carbohydrate/lipid effects, Ocular lesions, Dose-related risk of VTE from desogestrel-containing pills |
| Food/Dietary | No specific food restrictions. Grapefruit juice does not significantly interact with ethinylestradiol or gestodene. St. John's Wort (Hypericum perforatum) reduces contraceptive efficacy by inducing CYP3A4 metabolism; avoid concurrent use. High-fat meals may increase ethinylestradiol absorption slightly but no dose adjustment needed. |
| Clinical Pearls | GILDESS 1.5/30 is a combined oral contraceptive (COC) containing ethinylestradiol 30 µg and gestodene 75 µg. Gestodene is a third-generation progestin with high progestogenic activity and low androgenic effects, reducing acne and hirsutism. This formulation has a higher risk of venous thromboembolism (VTE) compared to second-generation COCs. Avoid in women with migraines with aura, hypertension (BP >160/100), or BMI >30 due to increased VTE risk. For missed pills: if one pill is missed, take it as soon as remembered and continue; if two or more pills are missed, take the last missed pill, use backup contraception for 7 days, and consider emergency contraception if unprotected intercourse occurred. |
| Patient Advice | Take one tablet daily at the same time, preferably in the evening, to reduce nausea. · If you miss a pill, follow the instructions in the package leaflet; if you miss more than one pill, use additional contraception (e.g., condoms) for 7 days. · Smoking increases the risk of serious cardiovascular side effects; do not smoke while taking this medication, especially if you are over 35. · Tell your doctor if you experience severe headache, chest pain, leg pain or swelling, visual disturbances, or jaundice. · This medication does not protect against sexually transmitted infections; use condoms for additional protection. · Vomiting or severe diarrhea within 4 hours of taking the pill reduces efficacy; consider it as a missed pill and use backup contraception. |
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