Comparative Pharmacology
Head-to-head clinical analysis: GILDESS FE 1 20 versus NORINYL 1 80 21 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GILDESS FE 1 20 versus NORINYL 1 80 21 DAY.
GILDESS FE 1/20 vs NORINYL 1+80 21-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive: ethinyl estradiol suppresses gonadotropin release; norethindrone induces progestational changes in endometrium and cervical mucus, preventing ovulation and fertilization.
Combination oral contraceptive containing norethindrone (a progestin) and ethinyl estradiol (an estrogen). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial morphology.
One tablet orally once daily for 21 days followed by 7 placebo tablets per 28-day cycle.
One tablet orally once daily for 21 days, followed by 7 days of no active treatment.
None Documented
None Documented
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.
Norethindrone: 8-11 hours; Mestranol: 12-24 hours (metabolized to ethinyl estradiol with half-life 20-27 hours). Steady-state after 5-7 days.
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%).
Renal (40-60% as metabolites), fecal (20-30%)
Category C
Category C
Oral Contraceptive
Oral Contraceptive