Pharmaceutical companies are trying to fill their drug portfolio by optimizing the marketed drugs. Most recently launched drugs are structurally similar to already known drugs, with only minor differences. The most common drug optimization methods are:
1. Reactive metabolites:
An excellent example of this is venlafaxine (Effexor) and desvenlafaxine ( Pristiq). Desvenlafaxine is the metabolite of venlafaxine. The difference is that desvenlafaxine having O-H instead of O-Me.
2. Deuterated Drugs:
Switching a hydrogen atom with a heavier isotope such as deuterium, pharma companies hope that the deuterated drug survives longer in the body and fewer side effects because it can make a stronger chemical bond than hydrogen.
3. Racemic switching:
Racemic switching is the redevelopment in a single enantiomer from a first approved drug as a racemate; a better example is the Nexium. It is a predecessor Prilosec, a mixture of both S and R isomers. When Prilosec’s patent expired in 2001, the drugmaker was ready with Nexium, which contains only the S-isomer.
The proliferation of "me-too" drugs leads to beneficial cost reductions. However, in the end, the real question is about pharmaceutical innovation. While “me too” fills the development pipeline, the creativity is fading away in the art of drug discovery?
