Comparative Pharmacology
Head-to-head clinical analysis: LEVLITE versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVLITE versus NORTREL 1 35 21.
LEVLITE vs NORTREL 1/35-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Levonorgestrel is a progestin that suppresses ovulation by inhibiting gonadotropin release (LH and FSH) and alters cervical mucus, endometrial thickness, and tubal motility.
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 (levonorgestrel 0.1 mg, ethinyl estradiol 0.02 mg) orally once daily for 21 days, followed by 7 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: 21-28 hours; clinical context: permits once-daily dosing
Norethindrone: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Renal: ~50% (30% as unchanged drug, 20% as metabolites); Fecal: ~40%; Biliary: minor
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive