Antidepressant — escitalopram
Depression is a feeling of sadness or hopelessness that affects a large proportion of the population at some point in their lives.
However, it can become a significant problem if these feelings take over a person's life to the extent that they can no longer function properly. Many drugs have been developed over the years to alleviate the symptoms of depression, ranging from the benzodiazepines such as diazepam and temazepam that are addictive and soporific, the tricyclic antidepressants and the monoamine oxidase inhibitors, which have substantial side-effect problems, to those with more recently-discovered modes of action like the selective serotonin reuptake inhibitors or SSRIs.
The SSRIs increase the activity of serotonin, also known as 5-hydroxytryptamine or 5-HT, by preventing its reabsorption, and such drugs have been shown to have much lower side-effect profiles than earlier classes of antidepressant.
One of the earliest SSRIs to reach the market was Lundbeck's citalopram. It is a racemic mixture, and the S-isomer alone possesses SSRI activity. Lundbeck has licensed the single isomer compound to Forest Labs in the US and Almiral Prodesfarma in Europe, and it is being assessed for safety as an SSRI.
Escitalopram has been found to have high selectivity for the reuptake of 5-HT, with low activity on the reuptake of both dopamine and epinephrine. Animal studies in rats showed it to be twice as effective and a hundred times more effective than the R-enantiomer at inhibiting serotonin reuptake.1
Phase III trials 'have been carried out in over 2,000 patients, and have shown the single isomer form of the drug to have significant activity in depressed patients.2 The company hopes the drug will be licensed for sale later this year.