Comparative Pharmacology
Head-to-head clinical analysis: LEVONORGESTREL versus PROGESTERONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVONORGESTREL versus PROGESTERONE.
LEVONORGESTREL vs PROGESTERONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
Progesterone binds to progesterone receptors (PR-A and PR-B) in target tissues, modulating gene expression to induce secretory changes in the endometrium, support pregnancy, and regulate gonadotropin secretion via negative feedback on the hypothalamic-pituitary axis.
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.
Oral: 200-400 mg daily in 1-2 divided doses; Intramuscular: 50-100 mg daily; Vaginal: 200-400 mg daily in 1-2 divided doses.
None Documented
None Documented
Clinical Note
moderateMedroxyprogesterone acetate + Digoxin
"Medroxyprogesterone acetate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Digoxin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateMedroxyprogesterone acetate + Digitoxin
"Medroxyprogesterone acetate may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Digitoxin
Terminal half-life: 24-30 hours (range 11-45 hours). This prolonged half-life supports once-daily or extended-cycle dosing in contraceptive formulations.
Elimination half-life: approximately 5-15 minutes for intravenous progesterone; terminal half-life of metabolites (pregnanediol) is about 2-8 hours, but clinical effects (e.g., endometrial transformation) persist for days due to receptor-mediated activity.
Renal: 45-60% (metabolites), Fecal: 32-45% (unchanged and metabolites). Biliary excretion contributes to fecal elimination.
Renal (50-60% as metabolites) and fecal (10-20%). Biliary excretion of metabolites occurs; enterohepatic recirculation may contribute to prolonged presence. Unchanged drug negligible in urine.
Category C
Category D/X
Progestin
Progestin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digitoxin."