Single-enantiomer drugs: Elegant science, disappointing effects

Peter R. Mansfield, David Henry, Anne Tonkin

Research output: Contribution to journalArticleResearchpeer-review

38 Citations (Scopus)

Abstract

Most new drugs are marketed as single enantiomers but many older agents are still available in racemic form. As these drugs reach the end of their patent life manufacturers become interested in marketing single enantiomer equivalents. This is called 'chiral switching' and it has been claimed that it will bring clinical benefits in terms of improved efficacy, more predictable pharmacokinetics or reduced toxicity. We reviewed the clinical evidence and prices for three recently marketed single enantiomer versions of widely used racemic drugs: escitalopram, esomeprazole and levosalbutamol. Claims of increased efficacy were based on comparisons of non-equivalent doses and any advantages seemed small and clinically unimportant. Prices of esomeprazole and levosalbutamol were higher than their racemic alternatives and we predict that these prices will remain high despite the market presence of generic versions of the racemates. Patent protection and a perception of superiority based on promotion rather than evidence will maintian price premiums for single enantiomer drugs that are not justified on the basis of clinical performance.

Original languageEnglish
Pages (from-to)287-290
Number of pages4
JournalClinical Pharmacokinetics
Volume43
Issue number5
DOIs
Publication statusPublished - 2004
Externally publishedYes

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Esomeprazole
Pharmaceutical Preparations
Citalopram
Marketing
Pharmacokinetics

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Mansfield, Peter R. ; Henry, David ; Tonkin, Anne. / Single-enantiomer drugs : Elegant science, disappointing effects. In: Clinical Pharmacokinetics. 2004 ; Vol. 43, No. 5. pp. 287-290.
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Single-enantiomer drugs : Elegant science, disappointing effects. / Mansfield, Peter R.; Henry, David; Tonkin, Anne.

In: Clinical Pharmacokinetics, Vol. 43, No. 5, 2004, p. 287-290.

Research output: Contribution to journalArticleResearchpeer-review

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