Common sense and characteristics of oral and injectable medicines

　　Oral. After oral administration, the drug may be absorbed by the gastrointestinal tract and act on the whole body, or remain in the gastrointestinal tract and act on the gastrointestinal region. Oral administration is the safest and most convenient method of medication, and it is also the most commonly used, suitable for most drugs and patients.

　　Injection. Injection drugs are divided into subcutaneous, muscle, vein, intrathecal injection and several kinds. Subcutaneous injection is the drug injection in the subcutaneous connective tissue, only applicable to a small amount of drugs, often used in skin tests; Intramuscular injection means that drugs are injected into muscles (mostly in the muscles of the arm). Oil agents, suspension agents and stimulant drugs should be injected into muscles. Intravenous injection, the dosage can be large, and the effect is fast, often used in emergency situations, the use of dangerous; If the dosage is larger, infusion method can be used to make the liquid slowly into the vein; Intrathecal injection can be used when the drug does not enter the spinal fluid or does not reach the desired concentration quickly.