Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus YASMIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 0 5 35 versus YASMIN.
CYCLAFEM 0.5/35 vs YASMIN
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 and drospirenone suppresses gonadotropins, inhibiting ovulation. Drospirenone has antimineralocorticoid activity, reducing water retention, and antiandrogenic activity.
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 0.03 mg / drospirenone 3 mg) orally once daily for 21 days, followed by 7 days of placebo.
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 30 hours for drospirenone; steady-state concentration is achieved after 10 days of daily dosing.
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.
Approximately 40% renal and 60% fecal after oral administration; metabolites are excreted as glucuronide and sulfate conjugates.
Category C
Category C
Oral Contraceptive
Oral Contraceptive