Shennong's herbal classics in the first century A.D. contained 365 kinds of drugs.
The newly revised Materia Medica in Tang Dynasty is the first pharmacopoeia in China, which contains 884 kinds of drugs.
Li Shizhen's Compendium of Materia Medica in Ming Dynasty is a scientific masterpiece, which lasted for 27 years, with 1.9 million words, * * 52 volumes, 1892 kinds of drugs,1/000 prescriptions and 160 illustrations. Widely circulated in the world is a glorious page in the history of drug development.
Development of related disciplines
Extraction of effective components of natural medicines: such as morphine, quinine, atropine, emetine, strychnine, cocaine, etc. Advances in chemistry and physiology gave birth to pharmacology. Buchheim founded pharmacology and became the first professor of pharmacology in the world. |
Pharmacology and related disciplines penetrate each other, learn from each other and promote each other, and many branches of disciplines are derived.
phylogeny
In ancient times, in order to survive, people learned from life experience that some natural substances could treat diseases and pains, which is the origin of drugs. Many of these practical experiences have been passed down to this day, such as drinking alcohol to relieve pain, rhubarb to promote diarrhea, neem pest control, willow bark to reduce fever and so on. Later, drugs also developed in the struggle between religious superstition and evil and in the pursuit of pleasure and longevity by feudal emperors. But it is more about integrating the accumulation and dissemination of practical experience of folk medicine into materia medica, which has been recorded in China, Egypt, Greece and India. For example, around the first century A.D., Shennong's Herbal Classic in China, Erbers's cursive script in Egypt and so on. tomorrow
Li Shizhen's Compendium of Materia Medica (1596) has made great contributions in the history of drug development, and it is a classic work of traditional medicine in China. The book has 52 volumes, about 1.9 million words, including 1892 kinds of drugs, illustrations 165438 frames and 6560 prescriptions. After the Renaissance in Western Europe (14th century), people's thinking began to get rid of religious shackles, thinking that everything has a cause and can be understood as long as it is observed objectively. The Swiss doctor ParaCelsus (1493- 154 1) criticized the idealism theory of the ancient Greek doctor Galen, ending the dark age of 1500 years in medical history. Later, the British anatomist W Harvey (1578- 1657) discovered blood circulation, which initiated a new era of experimental pharmacology.
The improvement of people's living standards requires more and better new drugs. The development of pharmaceutical science provides theoretical basis and technical conditions for the development of new drugs, and market economy competition also promotes the rapid development of new drugs. In recent ten years, the US Food and Drug Administration (FDA) has approved more than 20 new drugs to be listed every year. In recent years, many new drugs have been introduced in China, but innovation needs to be accelerated. The development of new drugs is a very strict and complicated process. Although each drug is different, pharmacological research is an essential key step. All clinically effective drugs have corresponding pharmacological effects, but drugs with positive pharmacological effects are not necessarily clinically effective drugs. For example, antihypertensive drugs can lower blood pressure, but antihypertensive drugs are not all antihypertensive drugs, and they are not necessarily good drugs that can reduce complications and prolong life. Therefore, the development and research of new drugs must have a process of gradual selection and elimination. In order to ensure the efficacy and safety of drugs for patients, the development of new drugs not only needs reliable scientific experimental results, but also governments of various countries have formulated laws and regulations on the approval and management of new drug production and sales to legally protect people's health and industrial and commercial economic rights and interests. The sources of new drugs include natural products, semi-synthetic and fully synthetic chemicals. In the past, the main method of drug selection was to rely on practical experience. Now we can infer from the plant taxonomy of effective drugs or the relationship between the chemical structure and pharmacological activity of effective drugs, find close relatives for screening, directionally synthesize a series of products, and then carry out pharmacological screening. In recent years, specific gene fragments of DNA have been separated and implanted into fast-growing bacteria or yeast cells by using DNA gene recombination technology, and a large number of needed protein drugs have been obtained. In addition, the chemical structure of existing drugs can be modified (semi-synthesized) or the dosage form can be changed, and drugs with better curative effect, less toxicity or more convenient application can also be obtained.
The research process of new drugs can be roughly divided into three steps, namely pre-clinical research, clinical research and after-sales research. Preclinical research includes systematic pharmacological research and observation of acute and chronic toxicity in animals. For drugs with selective pharmacological effects, it is necessary to determine the absorption, distribution and elimination process of the drug in animals before clinical trials. Preclinical research is to find out the action spectrum and possible toxic reactions of new drugs. miss
Clinical trials can only be carried out after the preliminary examination of the drug supervision department. The purpose is to ensure the safety of medication. In clinical research, the tolerance of new drugs was observed in 10 ~ 30 normal adult volunteers to find out the safe dose. Then select patients with specific indications and randomly divide them into two groups, set up a double control of known effective drugs and blank placebo (the blank control harmful to patients' health should not be used for acute and severe diseases), try to observe with a double-blind method (patients and medical staff can't distinguish between therapeutic drugs and control drugs), and then statistically analyze the treatment results to objectively judge the curative effect. At the same time, it is necessary to monitor the blood drug concentration and calculate the pharmacokinetic data (see chapter 3 for details). Generally, the number of subjects is not less than 300, which can be extended to more than three medical units for multi-center cooperative research after one hospital. For those new drugs that need to be used for a long time, 50 ~ 100 patients should be observed for half a year to one year. From this, the indications, contraindications, dosage and course of treatment and possible adverse reactions can be formulated, and can only be produced and listed after approval by the pharmaceutical administration department.
Post-marketing investigation refers to the social investigation and evaluation of new drugs after listing, focusing on the adverse reactions and long-term efficacy (including invalid cases) after long-term use in a wide range of popularization and application. Only by relying on the vast number of users (doctors and patients) can we make a correct historical evaluation.