Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 1 35 versus TRIPHASIL 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 1 35 versus TRIPHASIL 28.
CYCLAFEM 1/35 vs TRIPHASIL-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and norethindrone. Suppresses gonadotropin (FSH, LH) secretion via estrogen and progestin negative feedback, inhibiting ovulation. Progestin alters cervical mucus (sperm penetration) and endometrial receptivity.
Combination estrogen-progestin contraceptive; suppresses gonadotropin secretion, inhibits ovulation, alters cervical mucus and endometrium.
One tablet orally once daily. Each tablet contains 1 mg norethindrone and 0.035 mg ethinyl estradiol. Administer daily for 21 days followed by 7 days of placebo or no tablet.
1 tablet orally once daily for 28 days; each tablet contains levonorgestrel 0.050 mg and ethinyl estradiol 0.030 mg (6 days), levonorgestrel 0.075 mg and ethinyl estradiol 0.040 mg (5 days), levonorgestrel 0.125 mg and ethinyl estradiol 0.030 mg (10 days), followed by 7 inert tablets. The first dose is taken on the first Sunday after onset of menstruation or on day 1 of the menstrual cycle.
None Documented
None Documented
Half-life of norethindrone is 5-14 hours; ethinyl estradiol is 10-20 hours. Steady state reached after 5-7 days.
Levonorgestrel: terminal half-life 11-45 hours (mean 24-30 h); Ethinyl estradiol: terminal half-life 10-27 hours (mean 17 h). Steady-state reached after 5-7 days.
Renal 40-60% as glucuronide and sulfate conjugates, biliary/fecal 20-40%.
Renal (about 50-60% as metabolites, <10% unchanged), fecal (about 30-40% via biliary elimination). Ethinyl estradiol undergoes enterohepatic recirculation.
Category C
Category C
Oral Contraceptive
Oral Contraceptive