Comparative Pharmacology
Head-to-head clinical analysis: LESSINA 28 versus OVULEN 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LESSINA 28 versus OVULEN 21.
LESSINA-28 vs OVULEN-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of a progestin (levonorgestrel) and an estrogen (ethinyl estradiol). Inhibits ovulation by suppressing gonadotropin release; increases cervical mucus viscosity to impede sperm penetration, and induces endometrial changes that reduce implantation likelihood.
Combination estrogen-progestin oral contraceptive; inhibits gonadotropin release, suppressing ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial development.
One tablet (0.1 mg levonorgestrel and 0.02 mg ethinyl estradiol) orally once daily for 28 days, starting on the first day of menstrual cycle.
One tablet (ethinyl estradiol 0.05 mg and norethindrone 1 mg) orally once daily for 21 consecutive days, followed by 7 days without medication.
None Documented
None Documented
Terminal elimination half-life: 18-22 hours; clinically relevant for once-daily dosing.
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norethindrone: 5-14 hours (mean ~8 hours); terminal half-life supports once-daily dosing.
Renal: 30% as unchanged drug and metabolites; biliary/fecal: 70% as metabolites.
Renal: 50-60% as metabolites; fecal: 30-40% as conjugates; biliary excretion significant.
Category C
Category C
Oral Contraceptive
Oral Contraceptive