Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 7 7 7 versus GILDESS FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 7 7 7 versus GILDESS FE 1 20.
CYCLAFEM 7/7/7 vs GILDESS FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive. Ethinyl estradiol suppresses gonadotropin release (FSH, LH) via negative feedback on hypothalamic-pituitary axis; norethindrone induces endometrial changes that inhibit implantation and thickens cervical mucus.
Combination oral contraceptive: ethinyl estradiol suppresses gonadotropin release; norethindrone induces progestational changes in endometrium and cervical mucus, preventing ovulation and fertilization.
One tablet (norethindrone 0.5 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 0.75 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 1 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days. Dispensed in a 21-tablet pack with 7 placebo tablets. For contraception, take one tablet daily at same time each day for 28 days; begin next pack after 28-day cycle.
One tablet orally once daily for 21 days followed by 7 placebo tablets per 28-day cycle.
None Documented
None Documented
Terminal half-life: 5-13 hours (mean 8 hrs); clinical context: supports every-28-day dosing interval for intramuscular depot.
Ethinyl estradiol: terminal half-life approximately 13 hours (range 10-15 h). Desogestrel: metabolized to etonogestrel; etonogestrel terminal half-life about 28 hours (range 20-40 h). Clinical context: steady-state reached within 7-10 days.
Renal: ~50-60% as conjugated metabolites; Fecal: ~30-40% via bile; <1% unchanged.
Approximately 60-65% renal (as metabolites), 30-35% fecal (as metabolites and unchanged drug). Ethinyl estradiol and desogestrel metabolites are excreted primarily via urine and feces. Etonogestrel (active metabolite) is excreted mainly via feces (40%) and urine (32%).
Category C
Category C
Oral Contraceptive
Oral Contraceptive