Comparative Pharmacology
Head-to-head clinical analysis: CYCLAFEM 7 7 7 versus PHILITH.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CYCLAFEM 7 7 7 versus PHILITH.
CYCLAFEM 7/7/7 vs PHILITH
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive. Ethinyl estradiol suppresses gonadotropin release (FSH, LH) via negative feedback on hypothalamic-pituitary axis; norethindrone induces endometrial changes that inhibit implantation and thickens cervical mucus.
PHILITH is a combined oral contraceptive containing ethinyl estradiol and drospirenone. Ethinyl estradiol suppresses gonadotropin release, while drospirenone is a progestin with antiandrogenic and antimineralocorticoid activity, inhibiting ovulation and altering cervical mucus.
One tablet (norethindrone 0.5 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 0.75 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days, then one tablet (norethindrone 1 mg/ethinyl estradiol 35 mcg) orally once daily for 7 days. Dispensed in a 21-tablet pack with 7 placebo tablets. For contraception, take one tablet daily at same time each day for 28 days; begin next pack after 28-day cycle.
1 mg orally once daily
None Documented
None Documented
Terminal half-life: 5-13 hours (mean 8 hrs); clinical context: supports every-28-day dosing interval for intramuscular depot.
Terminal half-life 12 hours; clinically relevant for twice-daily dosing with steady state reached after 2-3 days.
Renal: ~50-60% as conjugated metabolites; Fecal: ~30-40% via bile; <1% unchanged.
Renal: 90% unchanged; biliary/fecal: 10% as metabolites.
Category C
Category C
Oral Contraceptive
Oral Contraceptive