Comparative Pharmacology
Head-to-head clinical analysis: DEMULEN 1 50 21 versus LARIN 1 5 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DEMULEN 1 50 21 versus LARIN 1 5 30.
DEMULEN 1/50-21 vs LARIN 1.5/30
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
DEMULEN 1/50-21 is a combined oral contraceptive containing ethinyl estradiol and ethynodiol diacetate. Ethinyl estradiol and progestins inhibit gonadotropin release (FSH and LH) from the pituitary, suppressing ovulation. Progestins also increase cervical mucus viscosity and alter endometrial receptivity, impeding sperm penetration and implantation.
Combination oral contraceptive: ethinyl estradiol suppresses FSH and LH, preventing ovulation; norethindrone induces endometrial changes and increases cervical mucus viscosity, impeding sperm penetration.
1 tablet (ethinyl estradiol 50 mcg, norethindrone 1 mg) orally once daily for 21 days, followed by 7 days off.
One tablet (norethindrone acetate 1.5 mg, ethinyl estradiol 30 mcg) orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo tablets.
None Documented
None Documented
Ethinylestradiol: 13 ± 3 h (biphasic; terminal phase used for dosing interval). Clinical context: steady-state achieved after ~3 days; missed dose may reduce contraceptive efficacy if >36 h.
Ethinyl estradiol: 13-19 hours; Norethindrone: 7-9 hours. Steady-state achieved in ~5-7 days.
Renal (approx. 50% as metabolites, <1% unchanged), fecal (approx. 40%, largely as ethinylestradiol conjugates), biliary (minor, enterohepatic recirculation of ethinylestradiol)
Renal (40% as metabolites, <10% unchanged); fecal (50% as metabolites); biliary (minor).
Category C
Category C
Combination Oral Contraceptive
Combination Oral Contraceptive