Comparative Pharmacology
Head-to-head clinical analysis: KELNOR versus QUARTETTE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KELNOR versus QUARTETTE.
KELNOR vs QUARTETTE
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 containing drospirenone, ethinyl estradiol, levomefolate calcium, and metformin. Drospirenone is a progestin with antimineralocorticoid and antiandrogenic activity. Ethinyl estradiol is an estrogen. Levomefolate calcium is a folate supplement. Metformin is a biguanide that decreases hepatic glucose production and improves insulin sensitivity.
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.
3 mg 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 is 12-14 hours; clinically this supports once-daily dosing with steady state achieved within 2-3 days.
Primarily renal excretion of unchanged drug (70-80%) and glucuronide conjugate (10-15%); biliary/fecal elimination accounts for <5%.
Renal excretion accounts for 55% (primarily as unchanged drug), biliary/fecal excretion 35%, and the remainder undergoes metabolic clearance.
Category C
Category C
Oral Contraceptive
Oral Contraceptive