Treatment by drugs requires the introduction of drugs into the body known as drug administration so that the drug can reach its target site and starts its action.
There are various routes of drug administration, major being the oral administration (when the drug is administered by ingestion through the mouth) and parenteral administration (injection of drugs through tissues and circulatory system).
The drugs introduced in the body by parenteral administration are absorbed quickly and hence are used in cases when rapid action of the drug is required.
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