Comparative Pharmacology
Head-to-head clinical analysis: NORTREL 1 35 21 versus PORTIA 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORTREL 1 35 21 versus PORTIA 21.
NORTREL 1/35-21 vs PORTIA-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol (estrogen) and norethindrone (progestin) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and inducing endometrial changes that reduce implantation likelihood.
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 for 21 days, followed by 7 days off, then repeat.
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: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Terminal elimination half-life: 24-30 hours; clinical context: steady-state reached after 5-7 days, allows once-daily dosing
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Renal (50-60% unchanged), fecal (30-40% as metabolites), minor biliary
Category C
Category C
Oral Contraceptive
Oral Contraceptive