Comparative Pharmacology
Head-to-head clinical analysis: KELNOR 1 50 versus ORTHO NOVUM 7 7 7 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KELNOR 1 50 versus ORTHO NOVUM 7 7 7 21.
KELNOR 1/50 vs ORTHO-NOVUM 7/7/7-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination hormonal contraceptive: ethinyl estradiol provides estrogenic activity, suppressing gonadotropin release; norethindrone acetate provides progestational activity, inhibiting ovulation and causing cervical mucus thickening.
Combined hormonal contraceptive; primarily suppresses ovulation via inhibition of gonadotropin release (LH and FSH) from the pituitary. Also induces changes in cervical mucus and endometrium.
One tablet (norethindrone 1 mg/ethinyl estradiol 50 mcg) orally once daily, taken at the same time each day for 21 days, followed by 7 days of placebo.
One tablet orally once daily for 21 days, followed by 7 days of no tablets. Each tablet contains norethindrone 0.5 mg/0.75 mg/1 mg and ethinyl estradiol 35 mcg, with biphasic or triphasic dosing per cycle.
None Documented
None Documented
Ethinyl estradiol: biphasic, terminal half-life 13-27 hours (mean ~17 h); norethindrone: monoexponential, half-life 5-14 hours (mean ~8 h). Steady-state achieved after 3-5 days. Accumulation may occur in patients with hepatic impairment.
Ethinyl estradiol: 13-27 hours; norethindrone: 8-14 hours; with multiple dosing, steady state after 5-7 days.
Renal: ~50% (as metabolites, primarily ethinyl estradiol glucuronide and sulfate conjugates; norethindrone metabolites). Fecal: ~35% (biliary excretion of conjugates followed by hydrolysis and elimination). Unchanged drug: <5%.
Renal: <10% unchanged; biliary/fecal: ~50% as metabolites; extensive enterohepatic recirculation.
Category C
Category C
Oral Contraceptive
Oral Contraceptive