Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus ORTHO NOVUM 7 14 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus ORTHO NOVUM 7 14 21.
CYCLAFEM 0.5/35 vs ORTHO-NOVUM 7/14-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing norethindrone (progestin) and ethinyl estradiol (estrogen). Inhibits gonadotropin release, suppressing ovulation. Increases cervical mucus viscosity and alters endometrium, reducing sperm penetration and implantation.
Combination estrogen-progestin contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
One tablet (0.5 mg norethindrone/35 mcg ethinyl estradiol) orally once daily for 21 days, followed by 7 placebo days (or no tablets) per cycle.
One tablet containing 0.5 mg norethindrone/0.035 mg ethinyl estradiol (white tablets) on days 1-14, then one tablet containing 1 mg norethindrone/0.035 mg ethinyl estradiol (peach tablets) on days 15-21, then no tablets for 7 days; repeated cycles.
None Documented
None Documented
Terminal elimination half-life of norethindrone is 5-14 hours (mean 7.6 hours); ethinyl estradiol half-life is 7-20 hours (mean ~13 hours). Steady-state is achieved within 5-7 days.
Norethindrone: 10-12 hours (terminal), ethinyl estradiol: 13-27 hours (terminal); clinical context: steady state achieved within 5-7 days
Renal excretion accounts for approximately 50-60% of the dose (as metabolites), with 30-40% excreted in feces via biliary elimination. Unchanged drug is minimal in urine.
Renal: ~40% as glucuronide and sulfate conjugates; Fecal: ~20%; Biliary: minor
Category C
Category C
Oral Contraceptive
Oral Contraceptive