Comparative Pharmacology
Head-to-head clinical analysis: KELNOR versus NORQUEST FE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KELNOR versus NORQUEST FE.
KELNOR vs NORQUEST FE
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.
NORQUEST FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone. Ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation. Norethindrone induces progestational changes in the endometrium, increasing cervical mucus viscosity, and also inhibits ovulation.
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, each tablet containing 1 mg norethindrone acetate and 20 mcg ethinyl estradiol (21 active tablets) followed by 7 ferrous fumarate tablets.
None Documented
None Documented
Terminal elimination half-life 12-15 hours; clinically relevant for once-daily dosing.
Terminal half-life: 6-8 hours. Clinical context: Supports once-daily dosing with sustained therapeutic effect.
Primarily renal excretion of unchanged drug (70-80%) and glucuronide conjugate (10-15%); biliary/fecal elimination accounts for <5%.
Renal: 80% (50% unchanged, 30% as metabolites); Fecal: 19%; Biliary: <1%
Category C
Category C
Oral Contraceptive
Oral Contraceptive