Chirally pure molecules or enantiomers are non-superimposable mirror images of each other with a chiral center (such as carbon, sulphur, nitrogen or phosphorous atom). An equimolar mixture of enantiomers forms a racemate. Chirally pure molecules (single enantiomers) are important in the field of drug discovery as the drug targets such as enzymes and receptors are enantioselective in nature. Clinical studies have demonstrated that chirally pure drugs exhibit different pharmacokinetic and metabolic profiles, reduced adverse events, improved safety profiles and similar therapeutic activity at lowered drug dosage as compared with the racemate in many therapeutic areas. However, since there is a low level of awareness on the advantages of chirally pure molecules among clinicians, pharmacists and patients in India, the Association of Physicians of India (API) developed this position statement to increase awareness on the concept of chirality and the associated advantages of using chirally pure drugs in certain therapeutic areas to maximize patient outcomes. This includes the clinical evidence associated with single enantiomers such as S-metoprolol, S-amlodipine, esomeprazole, escitalopram, levobupivacaine, cisatracurium, S-etodolac, dexketoprofen, levofloxacin in terms of efficacy and safety as compared with their racemates. In addition, the API also provides some tactical recommendations for clinicians, pharmacists, patients, regulatory body and pharmaceutical companies to increase awareness on chirally pure drugs and puts forth the need for expedited availability of chirally pure drugs in the Indian market.
© Journal of the Association of Physicians of India 2011.