Comparative Pharmacology
Head-to-head clinical analysis: PORTIA 21 versus TRIPHASIL 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PORTIA 21 versus TRIPHASIL 28.
PORTIA-21 vs TRIPHASIL-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Oral contraceptive: inhibition of ovulation by suppressing gonadotropin release; increases viscosity of cervical mucus, reducing sperm penetration; alters endometrial receptivity.
Combination estrogen-progestin contraceptive; suppresses gonadotropin secretion, inhibits ovulation, alters cervical mucus and endometrium.
One tablet (norgestimate 0.180 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 days of placebo.
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
Terminal elimination half-life: 24-30 hours; clinical context: steady-state reached after 5-7 days, allows once-daily dosing
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 (50-60% unchanged), fecal (30-40% as metabolites), minor biliary
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