Comparative Pharmacology
Head-to-head clinical analysis: LESSINA 21 versus TRI SPRINTEC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LESSINA 21 versus TRI SPRINTEC.
LESSINA-21 vs TRI-SPRINTEC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Suppresses gonadotropin release (FSH, LH) from pituitary, inhibiting ovulation. Causes cervical mucus thickening and endometrial alterations, impeding sperm penetration and implantation.
Combination of ethinyl estradiol and norgestimate suppresses gonadotropin release, inhibiting ovulation, and increases viscosity of cervical mucus to inhibit sperm penetration.
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days placebo or no tablets.
One tablet (0.035 mg ethinyl estradiol / 0.250 mg norgestimate) orally once daily for 21 days, followed by 7 days of placebo tablets. Repeat cycle.
None Documented
None Documented
17-21 hours (terminal elimination half-life; clinical significance: allows once-daily dosing, but missed doses increase risk of ovulation)
Norelgestromin: 28 hours; Ethinyl estradiol: 17 hours. Steady-state achieved within 7 days.
Renal (70% as unchanged drug and metabolites), fecal (30% as metabolites)
Renal: 50% (metabolites); Fecal: 35% (eliminated in bile); unchanged drug <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive