Comparative Pharmacology
Head-to-head clinical analysis: AFIRMELLE versus NORINYL 1 35 21 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AFIRMELLE versus NORINYL 1 35 21 DAY.
AFIRMELLE vs NORINYL 1+35 21-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Inhibits ovulation by suppressing gonadotropin release (FSH and LH). Also increases cervical mucus viscosity and alters endometrial receptivity.
Combination oral contraceptive containing norethindrone (progestin) and ethinyl estradiol (estrogen). Suppresses gonadotropin release (FSH, LH) via negative feedback on hypothalamic-pituitary-ovarian axis, inhibiting ovulation. Increases cervical mucus viscosity and alters endometrial structure to impair sperm penetration and implantation.
One tablet (0.1 mg levonorgestrel, 0.02 mg ethinyl estradiol) orally once daily for 21 days, followed by 7 days of placebo.
One tablet orally once daily for 21 consecutive days, followed by 7 days off therapy.
None Documented
None Documented
Terminal elimination half-life: 12–15 hours. Steady-state achieved within 5 days with Q12H dosing.
Norethindrone: 7-8 hours; Ethinyl estradiol: 13-27 hours (mean ~17 hours). Steady state achieved by day 10-14.
Renal: 50% as unchanged drug and metabolites; fecal: 40% as metabolites; biliary: ~10% as glucuronide conjugates.
Renal (50-60% as metabolites, primarily glucuronide and sulfate conjugates) and fecal (30-40% as metabolites). Less than 1% excreted unchanged.
Category C
Category C
Combined Oral Contraceptive
Combined Oral Contraceptive