Comparative Pharmacology
Head-to-head clinical analysis: ETHINYL ESTRADIOL AND LEVONORGESTREL versus SAFYRAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ETHINYL ESTRADIOL AND LEVONORGESTREL versus SAFYRAL.
ETHINYL ESTRADIOL AND LEVONORGESTREL vs SAFYRAL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination hormonal contraceptive; ethinyl estradiol provides estrogenic activity, levonorgestrel provides progestational activity, suppressing gonadotropin (LH and FSH) release from the pituitary, inhibiting ovulation, and altering cervical mucus and endometrial lining to reduce sperm penetration and implantation.
Safyral is a combination of ethinyl estradiol and drospirenone. Ethinyl estradiol is an estrogen that suppresses gonadotropin release, preventing ovulation. Drospirenone is a progestin with anti-mineralocorticoid activity, which may reduce fluid retention, and anti-androgenic activity, which may improve acne. It also increases cervical mucus viscosity, impeding sperm penetration.
One tablet containing 0.02-0.05 mg ethinyl estradiol and 0.1-0.15 mg levonorgestrel orally once daily for 21 days, followed by 7 days of placebo or no tablets.
One tablet (drospirenone 3 mg/ethinyl estradiol 0.03 mg) orally once daily for 24 days, followed by 4 days of placebo.
None Documented
None Documented
Ethinyl estradiol: 13-27 hours (terminal). Levonorgestrel: 18-30 hours (terminal). Clinical context: steady state achieved in 5-7 days; missed doses may require backup contraception.
16.3 hours (range 12-21 hours) for drospirenone; 32.5 hours (range 24-42 hours) for ethinyl estradiol (EE); clinical context: steady-state achieved after 10 days for drospirenone, 7 days for EE
Urine (40% ethinyl estradiol metabolites, 40% levonorgestrel metabolites); feces (40% ethinyl estradiol, 20% levonorgestrel).
Urine (40% as metabolites, 20% unchanged; fecal 30% as metabolites; biliary excretion contributes to enterohepatic circulation, prolonging elimination)
Category D/X
Category C
Estrogen
Oral Contraceptive Progestin/Estrogen