Comparative Pharmacology
Head-to-head clinical analysis: CYCLESSA versus LEVONEST.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLESSA versus LEVONEST.
CYCLESSA vs LEVONEST
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of estrogen (ethinyl estradiol) and progestin (desogestrel) inhibits ovulation by suppressing gonadotropin release, increases viscosity of cervical mucus to impede sperm penetration, and alters endometrial receptivity.
Levonorgestrel is a synthetic progestin that inhibits ovulation by suppressing luteinizing hormone (LH) surge, alters cervical mucus to impede sperm penetration, and induces endometrial changes that inhibit implantation.
One tablet (0.15 mg desogestrel/0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
One tablet (levonorgestrel 1.5 mg) orally as a single dose within 72 hours of unprotected intercourse.
None Documented
None Documented
Desogestrel: 38±13 hours (terminal); ethinyl estradiol: 14±3 hours (terminal). Steady-state reached after 7-10 days.
The terminal elimination half-life is approximately 24-30 hours. This relatively long half-life supports once-daily dosing and allows for stable plasma concentrations within 5-7 days of continuous use.
Urine (50-60% as metabolites, <10% unchanged); feces (30-40% as metabolites); enterohepatic circulation.
Renal excretion of conjugated metabolites accounts for approximately 60-80% of an administered dose; fecal elimination via bile accounts for 20-40%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive