[″ + derma, skin]
Under or inserted under the skin, as a hypodermic injection. A hypodermic injection may be given subcutaneously (under the skin), intracutaneously (into the skin), intramuscularly (into a muscle), intraspinally (into the spinal canal), or intravascularly (into a vein or artery). It is given to secure prompt action of a drug when the drug cannot be taken by mouth, when it may not be readily absorbed in the stomach or intestines or when it might be changed by the action of the gastric secretions, or it acts as an anesthetic about the site of injection.
SEE: anesthesia, local
When the injected substance is not intended for intravascular injection, the syringe plunger should be pulled back after the needle is inserted to determine if the needle is in a vein or artery. If blood is obtained, the needle must be repositioned and the procedure repeated. It may be necessary to use a fresh needle and syringe. Because medicines not intended for intravenous injection produce serious undesired effects when given by this route, do not inject the medicine if the needle is in a vessel. If the medicine is to be injected into an artery or vein, it must not be administered unless pulling back on the plunger permits blood to freely enter the syringe.
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