The positive outcome in multiple myeloma led to further derivative developments like lenalidomide. Decades later, in 1999, thalidomide was discovered to be effective in multiple myeloma. In 1964, thalidomide was fortuitously recognized to be effective in erythema nodosum leprosum (ENL). In consequence, thalidomide was withdrawn for four years. Thalidomide is another well-known instance causing many severe skeletal birth defections in children whose mothers had taken this medication during the first trimester of pregnancy. The year sildenafil got marketed by Pfizer for erectile dysfunction under the name Viagra ®, it held a 47% share of this problem’s market, and the total sales were USD 2.05 billion worldwide. Sildenafil citrate was an antihypertensive medication that got repurposed as retrospective clinical data analysis showed its positive effect on erectile dysfunction. So far, the most successful repurposed drugs have been found accidentally, and no systematic approach has been involved in the process. Drug repurposing was serendipitous and accidental in the past whenever a medication had shown an off-target or a new on-target effect, it was investigated for commercial exploitation.
Drug repurposing can emerge in different forms like repositioning, reformulation, and combination. Investigational medicines may have had a desirable safety profile in phase I/II clinical trials but never reached the market due to reasons unrelated to safety, such as lack of efficacy. This review aims to provide a complete insight into the drug repositioning strategy, especially the candidates that could be beneficial in managing MDD.ĭrug repurposing is the procedure of finding new indications for approved or investigational medications. Moreover, new antidepressant medications usually act on multiple intra- and extra-cellular markers, indicating their poly-pharmacology indications. Changes in inflammatory biomarkers, neurotransmitters, age-related, and genetic factors are among the mechanisms constituting the indications of medications. Various mechanisms have been associated with the prevalence of MDD, and these mechanisms directly influence medication selection. Due to the insufficient therapeutic response of patients to the available medications, the need for new medicines has attracted scientists worldwide. Īs a significant mental disorder, major depressive disorder (MDD) affects approximately 264 million globally. To apply a drug repositioning strategy, three main steps are needed to be concluded first, a molecule/substance should be suggested for the mentioned indication second, preclinical models, including animal and computational models, should be assessed and last the efficacy of medication should be analyzed. Since the safety profile of these medications was studied thoroughly before, the development of their formulation has been analyzed, and the medicines successfully passed the preclinical and clinical steps, the risk of failure decreases significantly. ĭrug repositioning, also called drug repurposing or re-tasking, is a promising strategy to introduce new indications for other therapeutic goals for an available drug in the market.
Īs the regulatory requirements for bringing a new medication to the market is becoming more challenging to meet, medication cost increases globally.
Despite the high rate of technological progress and improvements in knowledge of different diseases, the discovery of new medications demonstrated a lower speed.