**13. Drug discovery and preclinical trials**

The development of new drugs over the past 30 years has revolutionalized the practice of medicine and has for instance seen the increased use of new anti-hypertensives and drugs that reduce cholesterol synthesis or dissolve blood clots which led to a 50% reduction in the number of deaths from cardio-vascular diseases and stroke among other diseases.

### **13.1. Conventional approaches to drug discovery**

These are the classical approaches to drug discovery that do not initially involve detailed scientific study they include the following;
