Comparative Pharmacology
Head-to-head clinical analysis: LESSINA 28 versus PORTIA 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LESSINA 28 versus PORTIA 28.
LESSINA-28 vs PORTIA-28
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 oral contraceptive: estrogen (ethinyl estradiol) suppresses gonadotropin release, inhibiting ovulation; progestin (levonorgestrel) alters cervical mucus and endometrial lining.
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 (levonorgestrel 0.15 mg, ethinyl estradiol 0.03 mg) orally once daily
None Documented
None Documented
Terminal elimination half-life: 18-22 hours; clinically relevant for once-daily dosing.
Levonorgestrel: 24-30 hours; ethinyl estradiol: 12-15 hours. Clinical context: Steady-state achieved within 5-7 days.
Renal: 30% as unchanged drug and metabolites; biliary/fecal: 70% as metabolites.
Renal (60-70% as metabolites, 20-30% as levonorgestrel/ethinyl estradiol glucuronides), fecal (10-20%), biliary (minor).
Category C
Category C
Oral Contraceptive
Oral Contraceptive