Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus TRI SPRINTEC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus TRI SPRINTEC.
NORLESTRIN FE 1/50 vs TRI-SPRINTEC
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 and norgestimate suppresses gonadotropin release, inhibiting ovulation, and increases viscosity of cervical mucus to inhibit sperm penetration.
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 (0.035 mg ethinyl estradiol / 0.250 mg norgestimate) orally once daily for 21 days, followed by 7 days of placebo tablets. Repeat cycle.
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.
Norelgestromin: 28 hours; Ethinyl estradiol: 17 hours. Steady-state achieved within 7 days.
Norethindrone: 20% renal, 80% fecal. Ethinyl estradiol: 40% renal, 60% fecal.
Renal: 50% (metabolites); Fecal: 35% (eliminated in bile); unchanged drug <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive