Table of Contents
HISTORY OF DRUG DISCOVERY: ANCIENT TO MODERN
A drug is defined as a product or article intended for the use in diagnosis, cure, mitigation, treatment, or prevention of disease in humans or animals. Drugs can affect biologic systems in both positive and negative ways. Humans have been trying to gain knowledge of the effects of drugs for thousands of years.
Drug discovery and development has a long history that goes back to the early days of human civilization. In the ancient times, death and diseases were not believed as natural phenomena. Common maladies, such as colds or constipation, were accepted as part of existence in life and dealt with by means of herbal remedies as were available at that time. However, serious and disabling diseases were recognized differently. For example, people at that time thought that these diseases were of supernatural origin or they might be the result of a spell cast upon the victim by some enemy, visitation by a malevolent demon, or the work of an offended God who had either put some object (a dart, a stone, a worm) into the body of the victim or had abstracted the soul from the patient. The treatments were also applied accordingly such as the extraction of demon from the body or removing the evil cast or luring the errant soul back to its proper habitat within the body and many other magical/supernatural activities. Therefore, the witch or the sorcerers were the first doctors or ‘medicine men’ of ancient times.
EARLY WRITTEN RECORDS OF NATURAL DRUGS
The first drugs were discovered through accident and observation. In ancient times, humans tried different plants, animals and mineral substances and they found that some substances produced specific effects. They were then tried to use those substances that had beneficial effects to achieve desired results and they also passed their knowledge of these drugs from generation to generation.
The information passed from generation to generation expanded with the development of writing and the ability to record knowledge to include organized knowledge about drug substances. From the earliest written documents, we have found that the use of drugs such as herbs, powders, and poultices had a place in religion and mysticism as well as medicine.
Some of the examples of how drugs were discovered from the early human civilizations are mentioned below:
During the time of the legendary emperor Sheng Nong in 3500 BC, it is believed that the Traditional Chinese Medicine (TCM) have originated at that time. The Chinese pharmacopoeia is extensive. Some of the active ingredients from Chinese herbs have been used in Western drugs for example, reserpine from Rauwouofia is used for antihypertensive and emotional and mental control, and the alkaloid ephedrine from Mahuang is for the treatment of asthma.
Ancient papyrus held written records of early Egyptian medical knowledge. The Ebers Papyrus from around 3000 BC mentioned 877 prescriptions and recipes for internal medicine, eye and skin problems, and gynecology. The Ebers Papyrus is the oldest written text that mention enemas. The Kahun Gynaecological Papyrus is the oldest surviving medical text of any kind in ancient Egypt dating to 1800 BCE.
The Indian folk medicine is called Ayurvedic medicine which can be traced back 3000 – 5000 years and was practiced by the Brahmin sages of ancient times. The word Ayurveda refers to the ‘complete knowledge for long life’. A sacred text of Hinduism from the early iron age known as ‘Atharvaveda’ is one of the first Indian text that deals with medicine. The materials are extensive and are mostly based on herbal formulations. Some of the herbs have appeared in Western medicines like as cardamom and cinnamon. A physician in the 4th century AD named Susruta described the use of henbane as antivenom for snakebites.
There was an alternative form of medicine in India known as Unani medicine which progressed during the Indian sultanate and mughal periods. Unani medicine is very close to Ayurveda. Both are based on the theory of the presence of the elements in the human body. In Unani, the elements are considered to be fire, water, earth, and air. The followers of Unani medicine believed that these elements should present in different fluids and their balance leads to health and their imbalance leads to illness.
Some of the Greek medical ideas came from the Egyptians, Babylonians, and even Chinese and Indians. A Greek physician named Hippocrates is considered the “father of modern medicine’’. Hippocrates and his followers were first to give ideas of many diseases and medical conditions. The Hippocratic Corpus is a collection of around 70 early medical works from ancient Greece associated with Hippocrates and his students. Hippocrates is the one who began to categorize illnesses as acute, chronic, endemic and epidemic. Different terms like, “exacerbation, relapse, resolution, crisis, paroxysm, peak, and convalescence’’ also used by him.
Galen of Pergamon (a Greek physician, surgeon, philosopher) was one of the greatest physicians of the ancient world, as his theories and experimentation laid the foundation for modern medicine surrounding the heart and blood.
The Romans invented numerous surgical instruments for example forceps, scalpels, cautery, cross-bladed scissors, the surgical needle, the sound, and speculas. Romans also performed cataract surgery. They also extended the pharmacy practice of the Greeks. Dioscorides and Galen were two important physicians in Roman days. Dioscorides’s Materia Medica contains descriptions of treatments based on 80% plant, 10% animal, and 10% mineral products.
DRUG DISCOVERY AND DEVELOPMENT WITHIN THE MIDDLE AGES
The Middle Ages, from around 400 to 1500 AD, witnessed the decline of the Roman influence. This was also the time when plagues scourged several parts of Europe. Diseases like bubonic plague, leprosy, smallpox, tuberculosis, scabies and other infectious diseases were rampant. Several millions of people across the Europe succumbed to these diseases.
GREAT PERIODS OF DRUG DISCOVERY
The history of innovation and discovery of drugs can be divided into two great periods. The first period begins at the beginning of 19th century and ends toward 1930. The aim is to isolate and purify natural products and obtaining new compounds by chemical synthesis, and studying their physiological properties. Two generations of drugs were introduced in this period.
The second period is known as the ‘Golden Age of drug discovery’ which begins in 1935–1940, at the dawn of World War II. It starts around 1930 and introduces vitamins, hormones, sulfonamides, antibiotics, and their derivatives. It was followed by three more generations.
FOUNDATION OF CURRENT DRUG DISCOVERY AND DEVELOPMENT
The history of drugs dates back thousands of years, but many of the specific drugs used today are relatively recent.
|1817||Article about morphine and its effects published|
|1884||Rabies vaccine for dogs announced (Pasteur)|
|1890||Diphtheria antitoxin (Behring)|
|1894||Anti-diphtheria serum (Roux)|
|1915||First aspirin tablets made|
|1923||Diphtheria toxoid (Ramon)|
|1924||Barbiturate use began|
|1930||Intravenous pentobarbital use began|
|1940||Pantothenic acid (vitamin B5) synthesized|
|1946||Penicillin produced synthetically|
|1950||Anthelmintic properties of piperazine identified|
|1950||Measles (Katz, Enders)|
|1951||Effects of fluoride on dental health discovered|
|1955||First polio vaccine licensed|
|1986-1987||Hepatitis B (recombinant)|
|1987||First monthly heartworm preventive|
|1994||First monthly systemic flea treatment|
|1996||First monthly spot-on flea treatment|
|1997||First veterinary NSAID|
|2006-2007||Human papilloma virus (recombinant)|
BEGINNINGS OF MODERN PHARMACEUTICAL INDUSTRY
Despite the advances created within the 1800s, there have been solely some medication out there for treating diseases at the start of the decade.
Digitalis: Extracted from a plant known as digitalis, digitalis stimulates the internal organ muscles and was accustomed treat cardiac conditions.
Quinine: Derived from the bark of the Cinchona pubescens, quinine, antimalarial drug, was used to treat malaria.
Ipecacuanha: Extracted from the bark or root of the Cephaelis plant, ipecacuanha was accustomed treat infectious disease.
Aspirin: Extracted from the bark of tree, it was used for the treatment of fever.
Mercury: This was used for the treatment of syphilis.
More systematic analysis was being performed to get new medication from the first decade. bacteriologist used an arsenic compound, arspheamine, to treat syphilis. Gerhard Domagh found that the red dye Prontosil was active against streptococcic bacteria. Later, French scientists isolated the active compound to be sulfanilamide, and this gave rise to a brand new vary of sulpha medication against hosts of bacterium.
Throughout history, humans have incidentally and by design discovered new medication each in nature and through scientific experimentation. In addition to using plants, animals, and mineral substances solely, science has progressed in using not only these substances but also their changed forms and derivatives. New data within the areas of chemistry, pharmacological medicine, and drug use has led to fantastic growth within the drug business. New drugs that are life enhancing and life prolonging often being discovered and developed. Veterinary technicians will readily appreciate the contribution that drugs build within the care of our animal friends.
Evolution of drug discovery – Wiley-VCH