Comparative Pharmacology
Head-to-head clinical analysis: QUARTETTE versus TRI LEGEST FE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: QUARTETTE versus TRI LEGEST FE.
QUARTETTE vs TRI-LEGEST FE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing drospirenone, ethinyl estradiol, levomefolate calcium, and metformin. Drospirenone is a progestin with antimineralocorticoid and antiandrogenic activity. Ethinyl estradiol is an estrogen. Levomefolate calcium is a folate supplement. Metformin is a biguanide that decreases hepatic glucose production and improves insulin sensitivity.
Tri-Legest FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone acetate. It prevents ovulation by inhibiting gonadotropin release (FSH and LH) and alters cervical mucus and endometrial lining to impede sperm penetration and implantation.
3 mg orally once daily for 21 days followed by 7 days of placebo.
One tablet orally once daily for 28-day cycle: 21 days active tablets (norethindrone/ethinyl estradiol) followed by 7 days placebo. For contraception only.
None Documented
None Documented
Terminal elimination half-life is 12-14 hours; clinically this supports once-daily dosing with steady state achieved within 2-3 days.
Norethindrone: 7-8 hours; Ethinyl estradiol: 18 hours (terminal). Steady-state reached after 7 days; clinical contraceptive efficacy requires consistent dosing.
Renal excretion accounts for 55% (primarily as unchanged drug), biliary/fecal excretion 35%, and the remainder undergoes metabolic clearance.
Renal: ~60% (metabolites), Fecal: ~30% (metabolites), Biliary: minor (~5% as conjugates)
Category C
Category C
Oral Contraceptive
Oral Contraceptive