Comparative Pharmacology
Head-to-head clinical analysis: LEVORA 0 15 30 28 versus PORTIA 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVORA 0 15 30 28 versus PORTIA 21.
LEVORA 0.15/30-28 vs PORTIA-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation. Also induces changes in cervical mucus (increasing viscosity) and endometrium (reducing receptivity) to impair sperm penetration and implantation.
Oral contraceptive: inhibition of ovulation by suppressing gonadotropin release; increases viscosity of cervical mucus, reducing sperm penetration; alters endometrial receptivity.
One tablet orally once daily at the same time each day for 28 days (21 active tablets containing 0.15 mg levonorgestrel and 0.03 mg ethinyl estradiol, followed by 7 placebo tablets).
One tablet (norgestimate 0.180 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 days of placebo.
None Documented
None Documented
Ethinyl estradiol: 13-27 hours (terminal); Levonorgestrel: 11-45 hours (terminal, dose-dependent due to SHBG binding).
Terminal elimination half-life: 24-30 hours; clinical context: steady-state reached after 5-7 days, allows once-daily dosing
Renal: ~50% (as glucuronide and sulfate conjugates of ethinyl estradiol and levonorgestrel); Fecal: ~50% (enterohepatic recirculation).
Renal (50-60% unchanged), fecal (30-40% as metabolites), minor biliary
Category C
Category C
Oral Contraceptive
Oral Contraceptive