VIRYA – AN IMPORTANT ATTRIBUTE OF DRUG ACTION

In the context of drug action, the word Virya, as envisaged in the Ayurvedic classics by the ancient Acharyas, connotes different meanings in different contexts and ultimately projects factor of any drug by virtue of which it performs certain actions in the body. This comprehensive term is employed to explain lesser or greater potential factors in the drug in relation to different processes and procedures to achieve a desired effect in the body.

Many phenomena may lead to one effect and many effects can be caused by one single phenomenon. In view of this it becomes imperative to discriminate different processes vis-à-vis different actions. These processes or phenomena, again involve certain body humors in different body tissues and, thereby, causing certain local and systemic actions all culminating into the main action of the drug. It is with special reference to the site and disease where in the drug mainly acts, one can conveniently prefer to call it the main action of the drug. But each and every step of the entire phenomenon of drug action should be taken into account before evaluating the proper drug action. Obviously, the term ‘Virya’ had to be used in the general actions of drug as well as the particular actions of the drug. It is, however, agreed and accepted that the general and particular actions of the drug are complementary and supplementary to each other in so far as the total effect of drug is concerned. Actions bigger or smaller, therapeutic or otherwise, can only be explained on the principles of structure – function relationship in the drug and preference may ofcourse, be given to the main therapeutic action of the drug. If functions without potency is inconceivable,

Basic concepts of Ayurvedic pharmacology 105 the single connotation of Virya is illogical. This is the main reason why the word Virya has been used in a general and also in a specific sense.

The Ayurvedic principles of drug action have been described in the form of Rasa, Guna, Virya, Vipaka and Prabhava. If these are the principles through which the drug operates, the word ‘Virya’, then, should also be used for actions of Rasa, Vipaka, Guna and Prabhava. As Prabhava could not be rationally and practically proved it was put into the category of empirical treatment and as the other four could be rationally and practically demonstrated they were put into another group. Right in the beginning Virya was divided into two groups Chintya Virya and Achintya Virya –chintya Virya indicating Virya in general and Achintya Virya indicating Prabhava.

One who in trying to evaluate and understand the rationale behind these principles Prabhava should be excluded from the consideration. The remaining four are Chintya Viryas and, therefore, the relationship of Rasa, Vipaka, Guna and Virya with the general or specific actions of the drug should be understood. In simpler words ‘Virya’ will imply a specific factor in the drug which may be responsible for its therapeutic action and also other factors in the drug to understood by the terms Rasa, Guna, Vipaka and Virya, which may imply the general actions of the drug. This is how the face value of all the literature about the concept of Virya leads one to the above postulation. But, then, instances are found wherein the main actions of the drugs intended to be achieved in a particular disease – condition becomes explainable on the basis of Rasa, Vipaka and Guna only. In such a case, should the terms Rasa, Guna, Vipaka be used as Virya or else these very terms should be retained to explain their actions? At this juncture our attention is drawn to the following virgins described by Charaka.

Basic concepts of Ayurvedic pharmacology 106 1. Certain drugs manifest their action by virtue of their taste;

some by virtue of their potency or other qualities; some by Vipaka and others by their Prabhava.

2. Virya can be determined while in association with body (Adhivasa) or even immediately after coming into contact with the body (Nipata).

3. It is not that the various drugs and diets act only by virtue of their qualities. In fact they act by virtue of their own nature or qualities or both on a proper occasion in a given location, in appropriate condition and situations; the effect so produced is considered to be their action (Karma); the factor responsible for the manifestation of the effect is known as Virya; where they act is the Adhishtana (location); when they act is time (Kala); how they act is upaya (mode of action); what they accomplish is the achievement (Phala).

Studying all the three versions together one is constrained to conclude that the whole rationality of drug action has been explained in terms of structure – function relationship with reference to the special affinity for a particular site of drug action. If this be so the Dravya along with its Rasa goes to explain the chemical constitution, Vipaka goes to explain the changes in chemical constitution, of drug right from digestion to metabolism. The changes that take place in the drug during the metabolism are explained in terms of Gunas and desired chemical constitution intended to achieve the desired therapeutic action is understood as Virya. It is true that the substance has a dominating position in the whole phenomenon as the qualities and actions are inherent in it (Samavayi)but , the actions of substances find expression through qualities (Guna) only. This is the main reason why the actions of Rasa, Vipaka or Virya had been explained by

Basic concepts of Ayurvedic pharmacology 107 using certain terms which fall in the categories of Guna. This whole picture definitely requires to be elaborately described on logical grounds, cause and effect relationship, constitution and the rationality behind it.

In the coming pages an attempt has been made to make a theoretical thread – bare analysis of different aspects of Virya in relation to different constitution and actions of the drug. And an attempt will also be made to be made to pin point the site of action and jurisdiction of these terms. The Samprapti Vighatana being the Sunnum bonnum of the treatment and Shadupakramas being the therapeutic generalization of treatment will also be incorporated in this study of Virya, and a relationship among these will be established as and how befitting to the easy understanding of the concept of Virya.

RASA VIS A VIS THE CHEMICAL CONSTITUTION