Comparative Pharmacology
Head-to-head clinical analysis: BREVICON 28 DAY versus LESSINA 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BREVICON 28 DAY versus LESSINA 21.
BREVICON 28-DAY vs LESSINA-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 oral contraceptive containing ethinyl estradiol and levonorgestrel. Suppresses gonadotropin release (FSH, LH) from pituitary, inhibiting ovulation. Causes cervical mucus thickening and endometrial alterations, impeding sperm penetration and implantation.
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).
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days placebo or no tablets.
None Documented
None Documented
Norethindrone: 8-11 hours; Ethinyl estradiol: 13-27 hours; half-life for ethinyl estradiol allows once-daily dosing
17-21 hours (terminal elimination half-life; clinical significance: allows once-daily dosing, but missed doses increase risk of ovulation)
Renal: ~40% as metabolites and unchanged drug; fecal/biliary: ~60% as metabolites
Renal (70% as unchanged drug and metabolites), fecal (30% as metabolites)
Category C
Category C
Oral Contraceptive
Oral Contraceptive