Comparative Pharmacology
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus LEVONORGESTREL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus LEVONORGESTREL.
ETHINYL ESTRADIOL; ETONOGESTREL vs LEVONORGESTREL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ETHINYL ESTRADIOL is an estrogen; ETONOGESTREL is a progestin. The combination suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering endometrial receptivity.
Synthetic progestin that suppresses gonadotropin release (GnRH, LH, FSH) via negative feedback on the hypothalamic-pituitary-ovarian axis; inhibits ovulation, thickens cervical mucus, and alters endometrial lining.
One vaginal ring (0.120 mg etonogestrel/0.015 mg ethinyl estradiol per day) inserted vaginally and left in place for 3 weeks, followed by a 1-week ring-free period.
For emergency contraception: 1.5 mg orally as a single dose or 0.75 mg orally 12 hours apart. For hormonal contraception: 0.03 mg to 0.05 mg orally once daily in combined oral contraceptives; for progestin-only oral contraceptive (mini-pill): 0.03 mg orally once daily. For intrauterine system (IUD): 52 mg intrauterine device inserted for up to 5 years.
None Documented
None Documented
Clinical Note
moderateLevonorgestrel + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Levonorgestrel."
Clinical Note
moderateLevonorgestrel + Erythromycin
"The metabolism of Erythromycin can be decreased when combined with Levonorgestrel."
Clinical Note
moderateLevonorgestrel + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Levonorgestrel."
Clinical Note
moderateLevonorgestrel + Fluconazole
Ethinyl estradiol: ~13 hours (range 7-20 h); etonogestrel: ~25 hours (range 15-36 h). At steady state, elimination half-life extends to 20-30 h for etonogestrel.
Terminal half-life: 24-30 hours (range 11-45 hours). This prolonged half-life supports once-daily or extended-cycle dosing in contraceptive formulations.
Urine (60-70% as metabolites, <10% unchanged), feces (20-30% via biliary elimination).
Renal: 45-60% (metabolites), Fecal: 32-45% (unchanged and metabolites). Biliary excretion contributes to fecal elimination.
Category D/X
Category C
Progestin
Progestin
"The metabolism of Fluconazole can be decreased when combined with Levonorgestrel."