Comparative Pharmacology
Head-to-head clinical analysis: NORTREL 1 35 21 versus TRI SPRINTEC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORTREL 1 35 21 versus TRI SPRINTEC.
NORTREL 1/35-21 vs TRI-SPRINTEC
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.
Combination of ethinyl estradiol and norgestimate suppresses gonadotropin release, inhibiting ovulation, and increases viscosity of cervical mucus to inhibit sperm penetration.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
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: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Norelgestromin: 28 hours; Ethinyl estradiol: 17 hours. Steady-state achieved within 7 days.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Renal: 50% (metabolites); Fecal: 35% (eliminated in bile); unchanged drug <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive