Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus YAZ.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus YAZ.
NORLESTRIN 28 1/50 vs YAZ
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
Combination of ethinyl estradiol and drospirenone; suppresses gonadotropins (FSH and LH) inhibiting ovulation, and increases cervical mucus viscosity to impede sperm penetration. Drospirenone has antimineralocorticoid and antiandrogenic activity.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
One tablet (0.02 mg ethinyl estradiol and 3 mg drospirenone) orally once daily for 24 days, followed by 2 days of placebo.
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Terminal elimination half-life of drospirenone is 31.2-32.5 hours; ethinyl estradiol: 13-27 hours. Steady-state achieved after 10 days of daily dosing. Clinically, once-daily dosing maintains stable concentrations.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Approximately 50% of drospirenone is excreted renally (metabolites, with <10% unchanged), and 50% via feces (biliary) after hepatic conjugation. Ethinyl estradiol is primarily excreted renally (60%) and fecally (40%) as glucuronide and sulfate conjugates.
Category C
Category C
Oral Contraceptive
Oral Contraceptive