Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus PORTIA 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus PORTIA 28.
NORLESTRIN 28 1/50 vs PORTIA-28
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.
Combination oral contraceptive: estrogen (ethinyl estradiol) suppresses gonadotropin release, inhibiting ovulation; progestin (levonorgestrel) alters cervical mucus and endometrial lining.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
One tablet (levonorgestrel 0.15 mg, ethinyl estradiol 0.03 mg) orally once daily
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Levonorgestrel: 24-30 hours; ethinyl estradiol: 12-15 hours. Clinical context: Steady-state achieved within 5-7 days.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
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