1. Pharmacology
Chapter 15

2. Pharmacology
Pharmacology is the study of the nature, uses, and effects of drugs for medical purposes.
A pharmacist is a specialist who is licensed in formulating and dispensing medications.

3. Prescription vs. OTC
A prescription (Rx) is an order for medication, therapy, or a therapeutic device given (usually in writing) by an authorized person to a person properly authorized to dispense or perform the order.
A prescription drug is a medication that may be dispensed only with a prescription from an appropriately licensed professional such as a physician or dentist.
An over-the-counter (OTC) is a medication that may be dispensed without a written prescription.

4. Generic & Brand Name Drugs
A generic drug is usally named for its chemical structure and is not protected by a brand name or trademark. For example, diazepam is the generic name of a drug frequently used as a muscle relaxant.
A brand name drug is sold under the name given the drug by the manufacturer. A brand name is always spelled with a capital letter. For example, Valium is the brand name for diazepam.

5. Terms related to Pharmacology

6. Addiction is compulsive, uncontrollable dependence on a substance, habit, or practice to the degree that stopping causes sever emotional, mental, or physiologic reactions.
An adverse drug reaction (ADR), or an adverse drug event (ADE), is an undesirable drug response that accompanies the principal response for which the drug was taken.
A side effect is an extra response to the drug that is not what was intended, but does not pose a risk to the patient.

7. Compliance is the patient’s consistency and accuracy in following the regimen prescribed by a physician or other healthcare professional. As used here, regimen means directions or rules.
A contraindication is a factor in the patient’s condition that makes the use of a drug dangerous or ill advised.
A drug interaction occurs when the effect of one drug is modified (changed) when it is administered at the same time as another drug.
An idiosyncratic reaction is an unexpected reaction to a drug that is relatively unique to that individual.

8. A palliative is a substance that eases the pain or severity of a disease but does not cure it.
A placebo is a substance containing no active ingredients that is given for its suggestive effects. In research, a placebo identical in appearance with the material being tested is administered to distinguish between drug action and suggestive effect of the material under study.
Potentiation, also known as synergism, is a drug interaction that occurs when the effect of one drug is potentiated (increased) by another drug.

9. Routes of Drug Administration

10. Inhalation administration refers to vapor and gases taken in through the nose or mouth and absorbed into the bloodstream through the lungs. For example, the gases used for general anesthesia are administered by inhalation.
Oral administration refers to drugs taken by mouth to be absorbed from the stomach or small intestine. These drugs may be in forms such as liquids, pills, or capsules. An enteric coating is applied to some tablets or capsules to prevent the release and absorption of their contents until they reach the small intestine.

11. Percutaneous treatment means a procedure performed through the skin
Percutaneous treatment means a procedure performed through the skin. For example, a needle passed through the skin is used to aspirate fluid from a space below the skin.
Per- means through, cutane means skin, and –ous means pertaining to
Rectal administration is the insertion of medication in the rectum by use of either suppositories or liquid solutions. A suppository is medication in a semisolid form that is introduced into the rectum. The suppository melts at body temperature, and the medication si absorbed through the surrounding tissues.

12. With sublingual administration, the medication is placed under the tongue and allowed to dissolve slowly. Once dissolved, the medication is quickly absorbed through the sublingual tissue directly into the bloodstream.
Topical administration refers to the drugs, such as lotions, ointments, and eyedrops, that are applied for local action.
Transdermal deliver is a method of applying a drug to unbroken skin via a patch worn on the patient’s skin. The drug is absorbed through the skin and into systemic circulation.

13. Parenteral administration is the administration of medication by injection through a hypodermic syringe.
An intramuscular injection (IM) is made directly into muscle tissue.
A subcutaneous injection (SC) is made into the fatty layer just below the skin.
An intravenous injection (IV) is made directly into a vein.
A intradermal injection (ID) is made into the middle layers of the skin.

14. Common Drug Administration Abbreviations & Symbols
a.c. or ac - before meals
ad lib - as desired
b.i.d. or bid - twice a day
•c - with
NPO - nothing by mouth
p.c. or pc - after meals
p.r.n. or prn - as needed
p.o. or po - by mouth
qd - every day
q.h or qh - every hour
q.i.d. or qid - four times a day
> - greater than
< - less than
t.i.d. or tid - three times a day