Comparative Pharmacology
Head-to-head clinical analysis: BALZIVA 28 versus NORTREL 1 35 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BALZIVA 28 versus NORTREL 1 35 28.
BALZIVA-28 vs NORTREL 1/35-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
BALZIVA-28 is a combination estrogen-progestin oral contraceptive. Ethinyl estradiol provides estrogenic activity, while levonorgestrel acts as a progestin, primarily suppressing gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, and causing changes in cervical mucus and endometrium to reduce sperm penetration and implantation.
Combination of ethinyl estradiol and norethindrone inhibits gonadotropin secretion via negative feedback on the hypothalamic-pituitary-ovarian axis, suppressing ovulation. Additionally, increases cervical mucus viscosity and alters endometrial receptivity.
One tablet (0.5 mg levonorgestrel and 0.1 mg ethinyl estradiol) orally once daily for 28 days, starting on the first day of menstrual cycle.
One tablet (norethindrone 1 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days, followed by a 7-day placebo period (if using 28-day pack) or continuous if using 21-day pack with 7-day off. Start on first day of menstrual period.
None Documented
None Documented
2.5 hours; clinically relevant for dosing interval in renal impairment
Norethindrone: 5-14 hours (terminal); ethinyl estradiol: 13-27 hours (terminal). Context: steady-state after 5-7 days; dose adjustment in hepatic impairment.
Renal: 50-60% as unchanged drug; fecal: 30-40% as metabolites; biliary: <5%
Renal 60-70% (as glucuronide and sulfate conjugates), fecal 20-30% (via biliary excretion).
Category C
Category C
Oral Contraceptive
Oral Contraceptive