Comparative Pharmacology
Head-to-head clinical analysis: BREVICON 28 DAY versus NORTREL 0 5 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BREVICON 28 DAY versus NORTREL 0 5 35 21.
BREVICON 28-DAY vs NORTREL 0.5/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive; ethinyl estradiol and norethindrone suppress gonadotropin secretion (FSH and LH) via negative feedback, inhibiting ovulation. Additionally, alters cervical mucus consistency and endometrial lining to impede sperm penetration and implantation.
Combination hormonal contraceptive containing norethindrone (a progestin) and ethinyl estradiol (an estrogen). Norethindrone inhibits ovulation by suppressing gonadotropin release (LH and FSH) and alters cervical mucus and endometrial receptivity. Ethinyl estradiol provides negative feedback on the hypothalamic-pituitary-ovarian axis, further suppressing ovulation.
One tablet (0.5 mg norethindrone and 35 mcg ethinyl estradiol) orally once daily for 28 days (21 active tablets followed by 7 inert tablets).
1 tablet orally once daily for 21 days, followed by 7 days off. Each tablet contains 0.5 mg norethindrone and 35 mcg ethinyl estradiol.
None Documented
None Documented
Norethindrone: 8-11 hours; Ethinyl estradiol: 13-27 hours; half-life for ethinyl estradiol allows once-daily dosing
Norethindrone: terminal half-life approximately 7-8 hours. Ethinyl estradiol: terminal half-life approximately 13-27 hours, mean about 17 hours. Ethinyl estradiol exhibits a longer half-life due to enterohepatic recirculation and extensive tissue distribution.
Renal: ~40% as metabolites and unchanged drug; fecal/biliary: ~60% as metabolites
Norethindrone is primarily excreted renally (approximately 60-80% as metabolites) and approximately 20-40% fecally. Ethinyl estradiol is excreted renally (about 40%) and fecally (about 60%) as glucuronide and sulfate conjugates.
Category C
Category C
Oral Contraceptive
Oral Contraceptive