Drug Chirality

Explore how mirror-image drug molecules produce different pharmacological effects.

(R)-Thalidomide vs (S)-Thalidomide

C₁₃H₁₀N₂O₄

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About This Drug

Thalidomide is perhaps the most infamous example of chirality in medicine. Marketed in the 1950s as a "safe" sedative for pregnant women, it caused thousands of birth defects worldwide.

Drug Class

Sedative / Immunomodulator

FDA Status

Withdrawn, later reapproved with strict controls (REMS) for multiple myeloma and leprosy

First synthesized: 1954

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About This Drug

Thalidomide

The thalidomide disaster of the 1950s-60s showed that enantiomers can have drastically different biological effects. Even pure R-thalidomide racemizes in vivo.

Sedative / Immunomodulatorbeginner

Why Chirality Matters in Drugs

Same atoms, different effects - Mirror-image molecules bind differently to chiral receptors
Safety concerns - The wrong enantiomer can be toxic, inactive, or cause side effects
Chiral switches - Companies patent pure enantiomers as improved versions of racemic drugs
FDA policy - Since 1992, the FDA requires separate testing of each enantiomer