Comparative Pharmacology
Head-to-head clinical analysis: KELNOR versus TRI LO MILI.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KELNOR versus TRI LO MILI.
KELNOR vs TRI-LO-MILI
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combined oral contraceptive; inhibits ovulation by suppressing gonadotropin release (FSH and LH) primarily via progestational activity; increases viscosity of cervical mucus to inhibit sperm penetration; alters endometrium.
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.
KELNOR (norethindrone acetate and ethinyl estradiol) is a combined oral contraceptive. Typical adult dose: 1 tablet (norethindrone acetate 1 mg/ethinyl estradiol 20 mcg) orally once daily for 21 days, followed by 7 placebo tablets, starting on day 1 of menstrual cycle.
One tablet orally once daily for 21 days, followed by 7 days of placebo.
None Documented
None Documented
Terminal elimination half-life 12-15 hours; clinically relevant for once-daily dosing.
Terminal elimination half-life: 20-24 hours; allows once-daily dosing for contraceptive efficacy.
Primarily renal excretion of unchanged drug (70-80%) and glucuronide conjugate (10-15%); biliary/fecal elimination accounts for <5%.
Renal: approximately 50% as metabolites; biliary/fecal: approximately 40% as metabolites; 10% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive