Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus PORTIA 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus PORTIA 21.
NORLESTRIN 28 1/50 vs PORTIA-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
Oral contraceptive: inhibition of ovulation by suppressing gonadotropin release; increases viscosity of cervical mucus, reducing sperm penetration; alters endometrial receptivity.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
One tablet (norgestimate 0.180 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 days of placebo.
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Terminal elimination half-life: 24-30 hours; clinical context: steady-state reached after 5-7 days, allows once-daily dosing
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Renal (50-60% unchanged), fecal (30-40% as metabolites), minor biliary
Category C
Category C
Oral Contraceptive
Oral Contraceptive