Comparative Pharmacology
Head-to-head clinical analysis: FALLBACK SOLO versus PLAN B ONE STEP.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FALLBACK SOLO versus PLAN B ONE STEP.
FALLBACK SOLO vs PLAN B ONE-STEP
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
FALLBACK SOLO is a small molecule inhibitor of the Hedgehog signaling pathway. It binds to and inhibits Smoothened (SMO), a transmembrane protein that activates the GLI transcription factors. This inhibition blocks the aberrant activation of the Hedgehog pathway, which is implicated in the growth of certain cancers.
Levonorgestrel is a progestin that prevents pregnancy primarily by inhibiting ovulation and altering cervical mucus to impede sperm penetration. It may also interfere with fertilization and implantation.
100 mg orally once daily
One 1.5 mg tablet orally as a single dose within 72 hours of unprotected intercourse.
None Documented
None Documented
Terminal half-life: 12 hours (range 10–14 h); clinical context: once-daily dosing achieves steady state in 2.5 days
Terminal elimination half-life is approximately 24 hours (range 16-32 hours) for levonorgestrel. This supports single-dose administration for emergency contraception.
Renal: 80% unchanged; fecal: 15% as metabolites; biliary: 5%
Renal (approximately 50%), with fecal elimination accounting for the remainder. Metabolites are excreted primarily in urine as glucuronide conjugates.
Category C
Category C
Emergency Contraceptive
Emergency Contraceptive