Comparative Pharmacology
Head-to-head clinical analysis: FALLBACK SOLO versus PLAN B.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FALLBACK SOLO versus PLAN B.
FALLBACK SOLO vs PLAN B
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, a progestin, prevents pregnancy primarily by inhibiting ovulation and altering cervical mucus to impede sperm penetration. It may also inhibit implantation.
100 mg orally once daily
One 1.5 mg tablet (levonorgestrel) orally as a single dose, taken as soon as possible 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: 24-30 hours. Clinical context: The prolonged half-life supports single-dose regimen for emergency contraception; may be affected by obesity (shorter half-life in obese women).
Renal: 80% unchanged; fecal: 15% as metabolites; biliary: 5%
Renal (approximately 50% as unchanged drug and metabolites); fecal (approximately 40% as metabolites); less than 1% biliary.
Category C
Category C
Emergency Contraceptive
Emergency Contraceptive