Pharmaceutical companies are selling billions of dollars' worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

It is cheaper to manufacture only one of the enantiomers.

It is not important. Both enantiomers will be equally effective.

The left-handed version of the enantiomer is always the effective one.

One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.

Verified step by step guidance

Understand the concept of enantiomers: Enantiomers are molecules that are mirror images of each other, much like left and right hands. They are a type of stereoisomer, which means they have the same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientations of their atoms.

Recognize the significance of chirality in biology: Many biological molecules are chiral, and the two enantiomers can have very different effects in biological systems. This is because the shape of a molecule can affect how it interacts with biological targets, such as enzymes or receptors.

Consider the implications for drug effectiveness: One enantiomer of a drug may fit well into a biological target and produce the desired therapeutic effect, while the other enantiomer may not fit as well, making it less effective or even inactive.

Evaluate the potential for adverse effects: In some cases, the non-effective enantiomer can interact with other biological targets, potentially leading to side effects or toxicity. This is why it is crucial to use the correct enantiomer in pharmaceuticals.

Conclude with the importance of specificity: Using only the effective enantiomer can improve the safety and efficacy of a drug, which is why pharmaceutical companies invest in producing single-enantiomer drugs despite the potential for higher manufacturing costs.