Comparative Pharmacology
Head-to-head clinical analysis: PORTIA 28 versus TRI LEGEST 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PORTIA 28 versus TRI LEGEST 21.
PORTIA-28 vs TRI-LEGEST 21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive: estrogen (ethinyl estradiol) suppresses gonadotropin release, inhibiting ovulation; progestin (levonorgestrel) alters cervical mucus and endometrial lining.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH), inhibits ovulation, alters cervical mucus and endometrium.
One tablet (levonorgestrel 0.15 mg, ethinyl estradiol 0.03 mg) orally once daily
One tablet orally once daily for 21 days, followed by 7 tablet-free days. Each tablet contains norgestimate 0.18 mg/ethinyl estradiol 0.025 mg (days 1-7), norgestimate 0.215 mg/ethinyl estradiol 0.025 mg (days 8-14), norgestimate 0.25 mg/ethinyl estradiol 0.025 mg (days 15-21).
None Documented
None Documented
Levonorgestrel: 24-30 hours; ethinyl estradiol: 12-15 hours. Clinical context: Steady-state achieved within 5-7 days.
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norgestimate active metabolite (norelgestromin): 22-36 hours (mean ~28 hours). Steady-state achieved within 5-10 days.
Renal (60-70% as metabolites, 20-30% as levonorgestrel/ethinyl estradiol glucuronides), fecal (10-20%), biliary (minor).
Renal: approximately 50-60% as metabolites; fecal: approximately 40-50% (ethinyl estradiol and norgestimate metabolites excreted in bile and feces); less than 1% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive