Data expansion:
Drugs are substances used to prevent, treat and diagnose diseases. Theoretically speaking, drugs refer to all chemicals that can affect the physiological functions of organs and the metabolic activities of cells, belonging to the category of drugs, including contraceptives.
Classification:
According to the law, drugs are divided into two categories: prescription drugs and over-the-counter drugs (OTC). Prescription drugs refer to drugs that can only be used under medical supervision in consideration of medical safety and must be prescribed in writing by medical practitioners (such as doctors, dentists or veterinarians).
Over-the-counter drugs refer to those drugs that are quite safe without medical supervision and can be sold directly by pharmacies without prescription. In the United States, the Food and Drug Administration (FDA) is the official organization that decides which drugs need prescriptions and which drugs can be sold directly in pharmacies.
The FDA appreciates that after years of prescription management, the drugs sold in pharmacies have a good safety record. Ibuprofen (analgesic) was originally a prescription drug, but now it can also be bought in ordinary pharmacies. Every tablet, capsule and dose of medicine sold in general pharmacies actually contain less active ingredients than the corresponding prescription drugs.
In the United States, although it takes many years for a new drug to be invented and approved for marketing, the inventor or discoverer of the drug can own the patent of its chemical structure 17 years. And as long as the patent is valid, the drug is the private property of the inventor. Ordinary drugs (non-monopoly drugs) are not protected by patents. After the drug patent expires, the drug can be labeled as generic by all FDA-recognized manufacturers or drug dealers, and the price is lower than that when it is used as a monopoly drug.
Pharmacodynamics:
Two medical terms that affect the selection and application of drugs are pharmacodynamics (the effect of drugs on the body) and pharmacokinetics (the effect of the body on drugs). Pharmacokinetics not only discusses the effects of drugs (such as analgesia, lowering blood pressure and lowering plasma cholesterol level), but also studies where and how drugs act (that is, the mechanism of action).
Although the action of drugs is relatively easy to show, its action site and mechanism cannot be quickly clarified. For example, opioids and morphine have been used to relieve pain and treat depression for hundreds of years, but only recently have brain structures and brain chemical components related to analgesia and euphoria been discovered.
Drugs must reach the lesion site to take effect, which is also the importance of pharmacokinetics. When the drug works, it is necessary to keep enough dose in the affected area, but it cannot produce serious adverse reactions. Every doctor knows that choosing the right dose is a complex art of balance.