Comparative Pharmacology
Head-to-head clinical analysis: ENPRESSE 28 versus NORINYL 1 80 21 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENPRESSE 28 versus NORINYL 1 80 21 DAY.
ENPRESSE-28 vs NORINYL 1+80 21-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ENPRESSE-28 is a combined hormonal contraceptive containing ethinyl estradiol and desogestrel. It acts by suppressing gonadotropin release (FSH and LH) from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering the endometrium.
Combination oral contraceptive containing norethindrone (a progestin) and ethinyl estradiol (an estrogen). Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial morphology.
1 tablet (ethinyl estradiol 0.035 mg / norgestimate 0.25 mg) orally once daily for 21 days, followed by 7 placebo days.
One tablet orally once daily for 21 days, followed by 7 days of no active treatment.
None Documented
None Documented
Terminal elimination half-life is 18-24 hours, allowing once-daily dosing; steady-state achieved within 5-7 days.
Norethindrone: 8-11 hours; Mestranol: 12-24 hours (metabolized to ethinyl estradiol with half-life 20-27 hours). Steady-state after 5-7 days.
Primarily renal excretion as unchanged drug (70-80%) and glucuronide conjugate (15-20%); biliary/fecal elimination accounts for <5%.
Renal (40-60% as metabolites), fecal (20-30%)
Category C
Category C
Oral Contraceptive
Oral Contraceptive