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Standards

Although the U.S Food and Drug Administration (FDA) has the legal responsibility for deciding whether a drug may be distributed and sold, there are definite standards for drugs set by an independent committee of physicians, pharmacologists, pharmacists, and manufactures. This committee is called the United States Pharmacopeia (U.S.P). Two important standards of the U.S.P. are that the drug must be clinically useful (useful for patients) and available in pure form (made by good manufacturing methods). If a drug has U.S.P after its name, it has met with the standards of the Pharmacopeia

References

Libraries and hospitals have two large reference testing of drugs. The most complete and up-to date is the Hospital Formulary, which gives information about the characteristics of drugs and their clinical usage (application to patient care).

The Physicians’ Desk Reference (PDR) is published by a private firm, and drug manufacturers pay to have their products listed. The PDR is a useful reference with several different indices to identify drugs along with precautions, warnings about side effects, and information about recommended dosage and administration for each drug.

Administration

The various methods of administering drug are:

¨       Oral Administration. Drugs are given by mouth and are slowly into the bloodstream through the stomach or intestinal wall.

¨       Sublingual Administration. Drugs are not swallowed but are placed under the tongue and allowed to dissolve in the saliva.

¨       Rectal Administration. Suppositories (cone-shaped objects containing drugs) and aqueous solutions are inserted into the rectum. At times, drugs are given by rectum when oral administration presents difficulties, such as when the patient is nauseated and vomiting.

¨       Parenteral Administration. This type of administration is accomplished by injection of the drug from a syringe (tube) through a hollow needle placed under the skin, into a muscle into a vein, or into a body cavity.Several types of parenteral injections are:

1.       Subcutaneous injection (SC). This is also called a hypodermic injection, and it is given just under the skin.

The outer surface of the arm is a usual location for this injection.

2.       Intradermal injection. This shallow injection is made into the upper layers of the skin and is used chiefly in skin testing for allergic reactions.

3.       Intramuscular injection (IM). The buttock or upper arm is usually the site for this injection into muscle. When drugs are irritating to the skin or when a large volume of a long-acting drug is needed, IM injections are advisable.

4.       Intravenous injection (IV). This injection is given into the veins. It is given when an immediate effect from the drug is desired or when the drug cannot be safely given into other tissues. Good technical skill is needed for administering this injection, because leakage of drugs into surrounding tissues may result in irritation and inflammation.

5.       Intrathecal injection. This injection is made into body cavity, such as the peritoneal or pleural cavity. For example, nitrogen mustard is injected into the pleural cavity in people who have pleural effusions due to malign disease. The drug causes the pleural surfaces to adhere, thus obliterating the pleural space and preventing accumulation of fluid.

¨      Inhalation. Vapors, or gases, are taken into the nose or mouth and are absorbed into the bloodstream through the walls of the air sacs in the lungs. Aerosols (particles of drug suspended in air) are administered by inhalation, as many anesthetics. Examples of aerosols are pentamidine, used to treat a form of pneumonia associated with acquired immunodeficiency syndrome (AIDS), and various aerosolized medicines used to treat asthma (spasm of the airways).

¨      Topical Application. Drugs are locally applied on the skin or mucous membranes of the body. Antiseptics (agar infection) and antipruritics (against itching) are commonly used as ointments, creams and lotions. Transdermal patches are used to deliver drugs (such as estrogen, pain medications, and nicotine) continuously through the skin.

Table 4.1 ROUTES OF DRUG ADMINISTRAION

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