It should stand for prescription drugs, Rx, and OTC. Prescription drugs, referred to as Rx drugs for short, refer to drugs prescribed or approved by the national health administrative department to ensure drug safety, which need to be sold by doctors or other medical professionals with prescription rights and can be used under the supervision or guidance of doctors, pharmacists or other medical prescribers. Prescription drugs mostly belong to the following situations: 1, new drugs are on the market, and their activities or side effects need further observation. 2. Some drugs that can produce dependence, such as morphine analgesics and some hypnotics. 3, the drug itself is toxic, such as anticancer drugs. 4. Special drugs for treating certain diseases, such as cardiovascular and cerebrovascular diseases, must be prescribed by doctors after diagnosis and used under the guidance of doctors. In addition, prescription drugs are only allowed to advertise in professional medical newspapers and periodicals, not in the mass media.