Comparative Pharmacology
Head-to-head clinical analysis: OVRAL versus TRI NORINYL 28 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: OVRAL versus TRI NORINYL 28 DAY.
OVRAL vs TRI-NORINYL 28-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
OVRAL is a combination oral contraceptive containing ethinyl estradiol and norgestrel. It inhibits ovulation by suppressing gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus, reducing follicle-stimulating hormone (FSH) and luteinizing hormone (LH) release from the pituitary. Additionally, it increases cervical mucus viscosity and alters endometrial receptivity, impeding sperm penetration and implantation.
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.
One tablet (norgestrel 0.3 mg with ethinyl estradiol 0.03 mg) orally once daily for 21 days followed by 7 days of placebo.
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).
None Documented
None Documented
Norgestrel: 24–32 hours; Ethinyl estradiol: 12–18 hours; steady-state achieved after 5–7 days
Ethinyl estradiol: 17 ± 6 hours (terminal); Norethindrone: 10 ± 3 hours (terminal). Steady-state achieved after 7-14 days.
Renal (60% as metabolites, ~40% unchanged); biliary/fecal (40%)
Renal: 40% as metabolites; Fecal: 50% as metabolites; Biliary: minor; unchanged ethinyl estradiol excreted in urine <5%, norethindrone <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive