Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 1 35 versus LOW OGESTREL 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 1 35 versus LOW OGESTREL 21.
CYCLAFEM 1/35 vs LOW-OGESTREL-21
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 oral contraceptive. Suppresses gonadotropin release (FSH and LH) via estrogen (ethinyl estradiol) and progestin (norgestrel), inhibiting ovulation. Also increases cervical mucus viscosity and alters endometrium.
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 0.3 mg/ethinyl estradiol 30 mcg) orally once daily for 21 days, followed by 7 pill-free days.
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: 18-28 hours; ethinyl estradiol: 13-27 hours. Steady-state achieved after 5-7 days.
Renal 40-60% as glucuronide and sulfate conjugates, biliary/fecal 20-40%.
Ethinyl estradiol and norgestrel are excreted primarily as glucuronide and sulfate conjugates in urine (50-60%) and feces (30-40%).
Category C
Category C
Oral Contraceptive
Oral Contraceptive