Comparative Pharmacology
Head-to-head clinical analysis: NORTREL 1 35 21 versus TRI LO MILI.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORTREL 1 35 21 versus TRI LO MILI.
NORTREL 1/35-21 vs TRI-LO-MILI
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 oral contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on the hypothalamic-pituitary axis; norgestimate binds to progesterone receptors, inhibiting ovulation and altering cervical mucus and endometrial receptivity.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
One tablet 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: 20-24 hours; allows once-daily dosing for contraceptive efficacy.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Renal: approximately 50% as metabolites; biliary/fecal: approximately 40% as metabolites; 10% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive