Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 1 35 versus OGESTREL 0 5 50 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 1 35 versus OGESTREL 0 5 50 28.
CYCLAFEM 1/35 vs OGESTREL 0.5/50-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and norethindrone. Suppresses gonadotropin (FSH, LH) secretion via estrogen and progestin negative feedback, inhibiting ovulation. Progestin alters cervical mucus (sperm penetration) and endometrial receptivity.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity and alters endometrial development.
One tablet orally once daily. Each tablet contains 1 mg norethindrone and 0.035 mg ethinyl estradiol. Administer daily for 21 days followed by 7 days of placebo or no tablet.
One tablet (norgestrel 0.5 mg/ethinyl estradiol 50 mcg) orally once daily for 28-day cycle.
None Documented
None Documented
Half-life of norethindrone is 5-14 hours; ethinyl estradiol is 10-20 hours. Steady state reached after 5-7 days.
Norgestrel: ~45 hours (range 24-56 h) enabling once-daily dosing; Ethinyl estradiol: ~17 hours (range 10-27 h).
Renal 40-60% as glucuronide and sulfate conjugates, biliary/fecal 20-40%.
Renal: 50-60% as metabolites (glucuronide and sulfate conjugates of norgestrel and ethinyl estradiol); Fecal: 30-40% via biliary elimination; Unchanged drug: <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive