Comparative Pharmacology
Head-to-head clinical analysis: DEMULEN 1 50 28 versus LARIN FE 1 20.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMULEN 1 50 28 versus LARIN FE 1 20.
DEMULEN 1/50-28 vs LARIN FE 1/20
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive: Ethinyl estradiol and ethynodiol diacetate suppress gonadotropin secretion (LH, FSH) via negative feedback, inhibiting ovulation. Ethynodiol diacetate also increases cervical mucus viscosity and induces endometrial changes.
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 orally once daily for 28 consecutive days per cycle.
One tablet orally once daily for 21 consecutive days, followed by 7 days of placebo (ferrous fumarate) tablets per cycle.
None Documented
None Documented
Ethinylestradiol: terminal elimination half-life ~13-27 hours (mean ~17 hours); ethynodiol diacetate (as norethindrone): terminal elimination half-life ~8-11 hours; clinical context: achieved steady-state within 5-10 days; accumulation not significant due to dose interval.
Ethinyl estradiol: ~13 hours (range 7-20); norethindrone: ~8-11 hours. Steady-state reached in 5-7 days.
Ethinylestradiol and ethynodiol diacetate are extensively metabolized; urinary excretion accounts for ~40% of ethinylestradiol metabolites and ~50-60% of ethynodiol diacetate metabolites; fecal excretion accounts for ~30% of ethinylestradiol metabolites and ~35% of ethynodiol diacetate metabolites; biliary excretion contributes to enterohepatic circulation.
Renal (60% as metabolites, <10% unchanged); biliary/fecal (40%)
Category C
Category C
Combination Oral Contraceptive
Combination Oral Contraceptive