Comparative Pharmacology
Head-to-head clinical analysis: ELLA versus PREVIFEM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ELLA versus PREVIFEM.
ELLA vs PREVIFEM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Selective progesterone receptor modulator (SPRM) with antagonistic and partial agonistic activity. Delays or inhibits ovulation, alters endometrial receptivity, and impairs implantation.
PREVIFEM is a combination of ethinyl estradiol, an estrogen, and norgestimate, a progestin. It inhibits ovulation by suppressing gonadotropin release from the pituitary (FSH and LH). Additionally, it increases viscosity of cervical mucus, impeding sperm penetration, and alters the endometrium.
30 mg orally as a single dose within 120 hours of unprotected intercourse.
One tablet (0.075 mg norgestrel and 0.03 mg ethinyl estradiol) orally once daily at the same time each day for 21 consecutive days, followed by 7 placebo tablets.
None Documented
None Documented
Terminal half-life is approximately 24.7 hours (range 20–30 hours), allowing for single-dose emergency contraception.
20-24 hours; steady-state reached in 5 days
Primarily fecal (≈86%) with minimal renal excretion (≈10%). Biliary elimination of metabolites is also significant.
Renal (60% as metabolites, <10% unchanged), fecal (30%), biliary (10%)
Category C
Category C
Emergency Contraceptive
Emergency Contraceptive