Comparative Pharmacology
Head-to-head clinical analysis: LESSINA 21 versus NORLESTRIN 28 1 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LESSINA 21 versus NORLESTRIN 28 1 50.
LESSINA-21 vs NORLESTRIN 28 1/50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
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.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
None Documented
None Documented
17-21 hours (terminal elimination half-life; clinical significance: allows once-daily dosing, but missed doses increase risk of ovulation)
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Renal (70% as unchanged drug and metabolites), fecal (30% as metabolites)
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Category C
Category C
Oral Contraceptive
Oral Contraceptive