Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus GENCEPT 10 11 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus GENCEPT 10 11 28.
CYCLAFEM 0.5/35 vs GENCEPT 10/11-28
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 of ethinyl estradiol (estrogen) and levonorgestrel (progestin) inhibits ovulation by suppressing gonadotropin release, increases cervical mucus viscosity to impede sperm penetration, and 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 (ethinyl estradiol 0.01 mg/levonorgestrel 0.1 mg) orally once daily for 28 days. For the first 21 days, active tablets are taken; the next 7 days are placebo tablets.
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.
Terminal elimination half-life is approximately 8-12 hours. Steady state is achieved within 2-3 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 excretion accounts for approximately 70% of elimination (as unchanged drug and metabolites), with about 10% biliary/fecal. The remaining is metabolized.
Category C
Category C
Oral Contraceptive
Oral Contraceptive