Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN 1 20 versus TRI SPRINTEC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN 1 20 versus TRI SPRINTEC.
MICROGESTIN 1/20 vs TRI-SPRINTEC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing estrogen (ethinyl estradiol) and progestin (norethindrone acetate). Inhibits gonadotropin secretion (FSH, LH) via negative feedback, preventing ovulation. Also causes cervical mucus thickening and endometrial thinning.
Combination of ethinyl estradiol and norgestimate suppresses gonadotropin release, inhibiting ovulation, and increases viscosity of cervical mucus to inhibit sperm penetration.
One tablet (norethindrone acetate 1 mg / ethinyl estradiol 20 mcg) orally once daily for 21 consecutive days, followed by 7 days of placebo or no tablets.
One tablet (0.035 mg ethinyl estradiol / 0.250 mg norgestimate) orally once daily for 21 days, followed by 7 days of placebo tablets. Repeat cycle.
None Documented
None Documented
Norethindrone: 5.2-12.8 hours (mean ~8 hours); Ethinyl estradiol: 7-20 hours (mean ~13 hours); hepatic impairment prolongs.
Norelgestromin: 28 hours; Ethinyl estradiol: 17 hours. Steady-state achieved within 7 days.
Renal: 40% as metabolites, 20% as glucuronide and sulfate conjugates; Fecal: 35%; Biliary: <5%.
Renal: 50% (metabolites); Fecal: 35% (eliminated in bile); unchanged drug <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive