Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus NORTREL 1 35 21.
NORLESTRIN FE 1/50 vs NORTREL 1/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol and norethindrone acetate provides negative feedback on gonadotropin release, suppressing ovulation. Also causes cervical mucus thickening and endometrial thinning.
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.
One tablet (norethindrone 1 mg and ethinyl estradiol 50 mcg plus ferrous fumarate 75 mg) orally once daily for 28 days, with 21 active tablets and 7 placebo tablets.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
None Documented
None Documented
Norethindrone: 5-12 hours (mean 8 hours). Ethinyl estradiol: 11-16 hours. Clinical context: Steady state reached in 5-7 days.
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Norethindrone: 20% renal, 80% fecal. Ethinyl estradiol: 40% renal, 60% fecal.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive