Administration of drugs

Question 0

Four pharmacokinetic properties that determine the onset, intensity, and duration of drug action

Answer 0

1. Absorption: permits entry of drug into plasma
2. Distribution: drug may leave bloodstream and distribute into interstitial and intracellular fluids
3. Metabolism: drug biotransformed by metabolism in liver or other tissues
4. Elimination: drug and metabolites eliminated by urine, bile, or feces

Question 1

Pharmacokinetics

Answer 1

What the body does to a drug

Question 2

Enteral administration

Answer 2

By mouth

Can be oral, sublingual, or buccal

Question 3

Enteric coated preparations

Answer 3

Chemical envelope protects drug from stomach acid, delivers it to the intestine where the coating dissolves and drug is released

Question 4

Extended release preparations (ER or XR)

Answer 4

Slower absorption and longer duration of action

Good for drugs with short half lives

Question 5

Sublingual/buccal

Answer 5

Drug diffuses through capillary network and directly enters systemic circulation

Question 6

Parenteral

Answer 6

Introduces drugs directly into systemic circulation
Used for drugs that are poorly absorbed or unstable in GI tract
Provides the most control over dosage to the body
Can be intravascular, intramuscular, or subcutaneous

Question 7

Intravenous (IV)

Answer 7

Most common parenteral route
Maximum effect and control over amount of drug delivered
Can be injected as bolus or IV infusion
Substance rapidly diluted by blood

Question 8

Intramuscular (IM)

Answer 8

Aqueous solutions absorbed rapidly

Specialized depot preparations absorbed slowly- consist of suspension of drug in nonaqueous vehicle

Question 9

Subcutaneous (SC)

Answer 9

Absorption via simple diffusion, slower than IV
Minimizes risk of hemolysis and thrombosis
Constant, slow, sustained effects
Not used with drugs that cause tissue irritation
Ex) heparin and insulin

Question 10

Oral inhalation

Answer 10

Rapid delivery across mucous membranes of respiratory tract and pulmonary epithelium
Drugs that are gases and can be dispersed in aerosol used
Used for respiratory disorder
Ex) albuterol

Question 11

Nasal inhalation

Answer 11

Directly into nose

Ex) oxymetazoline, desmopressin

Question 12

Intrathecal/intraventricular

Answer 12

Introduced directly into cerebrospinal fluid to bypass blood-brain barrier
Ex) amphotericin B

Question 13

Topical

Answer 13

Used for local effect

Question 14

Transdermal

Answer 14

Application of drugs to skin via transdermal patch
Sustained delivery of drugs
Ex) nitroglycerin

Question 15

Rectal

Answer 15

Minimizes biotransformation by liver and destruction by GI system
Absorption often erratic and incomplete