Comparative Pharmacology
Head-to-head clinical analysis: TRI NORINYL 28 DAY versus TRIPHASIL 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRI NORINYL 28 DAY versus TRIPHASIL 21.
TRI-NORINYL 28-DAY vs TRIPHASIL-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol and norethindrone. Suppresses gonadotropin (FSH and LH) release via negative feedback, inhibiting ovulation. Also increases viscosity of cervical mucus and alters endometrial lining to reduce implantation likelihood.
Combination of ethinyl estradiol and levonorgestrel suppresses gonadotropin release, inhibiting ovulation; alters cervical mucus to impair sperm penetration and endometrial receptivity.
One tablet orally once daily for 21 days, followed by one placebo tablet orally once daily for 7 days. Each active tablet contains 0.035 mg ethinyl estradiol and 0.5 mg norethindrone (7 days), 0.035 mg ethinyl estradiol and 1.0 mg norethindrone (9 days), and 0.035 mg ethinyl estradiol and 0.5 mg norethindrone (5 days).
One tablet orally daily for 21 days, followed by 7 drug-free days. Each tablet contains levonorgestrel 0.05 mg and ethinyl estradiol 0.03 mg (days 1-6), levonorgestrel 0.075 mg and ethinyl estradiol 0.04 mg (days 7-11), and levonorgestrel 0.125 mg and ethinyl estradiol 0.03 mg (days 12-21).
None Documented
None Documented
Ethinyl estradiol: 17 ± 6 hours (terminal); Norethindrone: 10 ± 3 hours (terminal). Steady-state achieved after 7-14 days.
Levonorgestrel: 10-45 hours (terminal, biphasic); ethinyl estradiol: 10-27 hours (terminal, triphasic). Clinical context: Steady state reached after 7-14 days with daily dosing.
Renal: 40% as metabolites; Fecal: 50% as metabolites; Biliary: minor; unchanged ethinyl estradiol excreted in urine <5%, norethindrone <1%.
Renal: 30-50% (ethinyl estradiol and levonorgestrel metabolites as glucuronide and sulfate conjugates). Fecal: 30-50% (biliary excretion of unconjugated metabolites). Unchanged drug: negligible.
Category C
Category C
Oral Contraceptive
Oral Contraceptive