Comparative Pharmacology
Head-to-head clinical analysis: LARIN 1 20 versus LARIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LARIN 1 20 versus LARIN FE 1 20.
LARIN 1/20 vs LARIN FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity, inhibiting sperm penetration; alters endometrial receptivity.
LARIN FE 1/20 is a combination oral contraceptive containing ethinyl estradiol and norethindrone. It inhibits ovulation by suppressing gonadotropin release (FSH and LH) from the pituitary, increases viscosity of cervical mucus, and alters endometrial receptivity.
One tablet (0.1 mg levonorgestrel/20 mcg ethinyl estradiol) orally once daily for 21 days followed by 7 placebo days.
One tablet orally once daily for 21 consecutive days, followed by 7 days of placebo (ferrous fumarate) tablets per cycle.
None Documented
None Documented
Norethindrone: 7.6 hours (range 5-14); Ethinyl estradiol: 13.2 hours (range 8-20). Clinical context: Steady-state achieved within 5-10 days.
Ethinyl estradiol: ~13 hours (range 7-20); norethindrone: ~8-11 hours. Steady-state reached in 5-7 days.
Approximately 60% renal (30% norethindrone, 30% ethinyl estradiol metabolites) and 40% fecal (biliary excretion of conjugates).
Renal (60% as metabolites, <10% unchanged); biliary/fecal (40%)
Category C
Category C
Combination Oral Contraceptive
Combination Oral Contraceptive