Understanding of Drug repurposing in Ayurveda
In past decade, it is felt that drug discovery is time consuming (large gestation) and an uncertain million dollar affair. The process from a compound to drug almost take 15 years and at least 2 billion dollars are required to transform a compound in to a drug. Denovo drug delivery process has a high attrition rate precisely in a 1 million screened compounds only I reaches to clinical uses showing tract attrition.
Now, a clinical phases faces significant ethical issues and stricter norms, intact getting regulatory clearance from the central govt or state Govts is difficult. It is a marathon.
Hence considering all this scientist are now moving to more pragmatic approach for drug discovery and they are –
- Drug repurposing
- Reverse pharmacology
Today , we will only discuss drug repurposing
Drug repurposing – Identifying , developing and commercialising new uses for existing or abandon drug. Eg. Hydroxychloroquine
Drug Repositioning – Finding new uses outside the scope of original medical indication for existing drug.
Drug Reprofiling – Reducing the risk and cost associated with drug development with the advantage that the drug has already undergone a pre clinic and clinical testing. Eg. Thelidomide uses for Nausea in 1950s and for Leprosy in 1980s.
Drug Rediscovery – Investigating new uses for currently prescribed drugs.
Drug reformulation – Finding ways to modify a formulation to allow a drug to enter a new market/therapeutics. Eg. Triphala and Balachaturbhadra.
Therapeutic Switching – Opening up a new possibility for a old medicine that were not appreciated at the time of original discovery and can be therapeutically different through new formulations.
Indication Switching – Exploiting established drugs that have already been approved for treatment.
Need of the repurposing –
– Gestational time of de novo drug discovery
- Success Rate
- Data Availability
How Drug Repurposing is designed –
- Machine Learning
- Network Analysis
- Analysis of omic data
Let us discuss the few points regarding drug repurposing
- Drug-Drug Similarity — Chemical Structure, targets, side effect, gene ontology
- Disease-Disease Similarity — Phenotype , Human phenotype ontology, gene ontology.
Indian traditional Medicine was a geographically influenced/dominated health management system of south east Asia. Time to time it incorporated/ adopted the prevailing science of era for health management viz. Herbominerals and metal bhasmas during renaissance of alchemy proving its development has spatiotemporal contribution.
Ayurveda concepts of repurposing , therapeutic switching, new indication, drug reprofiling, therapeutic potentiation or near terms may be seen scattered in classics.
Why it was need during ancient time –
- Geographical limitations of drug availability.
- Seasonal Limitation
- Environmentally very concerned
- Storage and transport
Ancient Tricks of Drug Repurposing –
- Sewan Kaal
These six tricks (which I thought) were traditional repurposing techniques for utilising the available drugs to the disease prevailing.
Three types of Treatment in Ayurveda
- Dosha pratyanik
- Vyadhi Pratyanik
- Ubhaya pratyanika
- Give two examples of Anupana which change the indication of used drug.
- Give example of some other drug which is indicated in different diseases at different doses.
- Give two other examples of Bhavana.
- Which of the following is not the prophylactic/therapeutic indication of Hydrocholoroquinone
- Rheumatoid arthritis
- What do you understand about gene ontology?
- What was the thought behind the pious collection of drugs in ancient time?
- Write two methods to reduce the cost of drug development research.
- Which of the following is the treatment method described in Ayurveda
- Dosha pratyanika chikitsa
- Vyadhi pratyanika chikitsa
- Ubhya pratyanika chikitsa
- All of above
- Write two more traditional techniques of drug repurposing.
- Ayurvedic drugs act through which of the following principle
- Rasa & guna
- Virya & vipaka
- All of above
For further reading:
Acharya Priyavrat Sharma, Dravyaguna vigyan part I & II
Charak Samhita, purvardha & Utarardha
Sharangdhar Samhita, Madhyam Khand.
Bhav Prakash Nighantu
Drug repurposing ; a promising tool to accelerate the drug discovery process; drug discovery today; vol. 24 (10) https://doi.org/10.1016/j.drudis.2019.06.014
An update on drug repurposing: rewritten saga of the drugs fate; Biomedicine and pharmacotherapy; Vol 110; https://doi.org/10.1016/j.biopha.2018.11.127