Comparative Pharmacology
Head-to-head clinical analysis: GENCEPT 10 11 28 versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: GENCEPT 10 11 28 versus NORTREL 1 35 21.
GENCEPT 10/11-28 vs NORTREL 1/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol (estrogen) and levonorgestrel (progestin) inhibits ovulation by suppressing gonadotropin release, increases cervical mucus viscosity to impede sperm penetration, and alters endometrial receptivity.
Combination of ethinyl estradiol (estrogen) and norethindrone (progestin) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and inducing endometrial changes that reduce implantation likelihood.
One tablet (ethinyl estradiol 0.01 mg/levonorgestrel 0.1 mg) orally once daily for 28 days. For the first 21 days, active tablets are taken; the next 7 days are placebo tablets.
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
None Documented
None Documented
Terminal elimination half-life is approximately 8-12 hours. Steady state is achieved within 2-3 days.
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Renal excretion accounts for approximately 70% of elimination (as unchanged drug and metabolites), with about 10% biliary/fecal. The remaining is metabolized.
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive