Anti-Cancer Potential of Some Commonly Used Drugs.

Cancer is a global concern leading to millions of deaths every year. A declining trend in new drug discovery and development is becoming one of the major issues among the pharmaceutical, biotechnology industries and regulatory agencies. New drug development is proven to be a very lengthy and a costly process. Launch of a new drug takes 8-12 years and huge investments. Success rate in oncology therapeutics is also low due to toxicities at the pre-clinical and clinical trials level. Many oncological drugs get rejected at very promising stage showing adverse reactions on healthy cells. Thus, exploring new therapeutic benefits of the existing, shelved drugs for their anti-cancerous action could result in a therapeutic approach preventing the toxicities which occurs during clinical trials. Drug repurposing has the potential to overcome the challenges faced via conventional way of drug discovery and is becoming an area of interest for researchers and scientists. Although very few in vivo studies are conducted to prove the anti-cancerous activity of the drugs. Insufficient in vivo animal studies and lack of human clinical trials are the lacuna in the field of drug repurposing. This review focuses on the aspect of drug repurposing for cancer therapeutics. There are various studies which show that drugs approved for clinical indications other than cancer have shown promising anti-cancer activities. Some of the commonly used drugs like Benzodiazepines (Diazepam, Midzolam), Antidepressants (Imipramine, Clomipramine, and Citalopram), Antiepileptic (Valporic acid, Phenytoin), Anti diabetics (metformin) etc., have been reported to show potential activity against the cancerous cells.