test 1 Flashcards
Chemical name
– chemical structure of drug
Generic name
– nonproprietary name
Trade/Brand name
– name owned and marketed by a pharmaceutical company
Contraindications
Contains warnings as to particular patients or situations in which the drug should not be used
Drug Interactions
- Modification of the effect of a drug when given with another drug
- Results in either a decrease or increase in the action of the drug
- Beneficial (Drug combination therapy)
- Harmful (Adverse side effects)
Three Types of Drug Interactions
- Additive interactions
- Synergistic interactions
- Potentiation interactions
Additive Drug Interactions
-sum of the effects of two drugs given together is equal to each of them given separately but at the same time
Synergistic Drug Interactions
-summation of each individual drug’s activity exceeds the sum of the two individual drugs
Potentiation Drug Interactions
-One drug (which has no direct effect) increases the response of the other drug, which normally has a lesser effect
Adverse Drug Reactions (ADR)
•Unintended side effects from a drug
•At least 5% of hospitalizations are the result of an adverse drug reaction
– tremors, bronchospasms, headaches, vomiting, photosensitivity etc.
•Not all ADRs are allergies
Drug Allergy
- Drug allergies are immune-mediated and induce a hypersensitivity reaction (Mild-hives, Severe-anaphylactic shock)
- Drug allergies are only one example of an ADR
Pharmacokinetics
- what the body does to a drug
- Absorption, distribution, metabolism, and elimination
Pharmacodynamics
-what the drug does to
the body
Absorption
How a drug moves from its site(s) of administration into plasma
absorption of the drug is based on
- size of the drug (smaller the easier)
- ionization of the drug (non-ionized pass through membrane easier)
- lipid solubility (lipophilic easier to pass through than hydrophilic)
Distribution (pharmacokinetics)
-The dissemination of a drug throughout the body, such as plasma, tissues, or organs
•Bloodstream is the major vehicle for distribution
Distribution Influenced by
- Blood flow
- Fat or water solubility
- Protein binding
Metabolism (pharmacokinetics)
-The biotransformation of a drug into other secondary components called metabolites
•Preparing drug for elimination
•Drug becomes more water soluble to enhance elimination
Elimination (pharmacokinetics)
- The processes that remove a drug from the body in urine, bile, or feces
- Drugs can also be excreted via the pulmonary system, skin, hair, saliva, and expired air
routes of administration determined by
- Determined by property of drug (Water or lipid soluble, Ionization)
- Desirability of a rapid onset
- Need for long-term treatment
- Restriction of delivery to a local site
Enteral (through digestive tract) Administration
- Administering drug by mouth (Swallowed, Under tongue (sublingual), Between gums and cheek (buccal))
- Most common
- Most convenient
- Most economical
- Safest
Oral Administration
•Easily self administered •Toxicities/overdoses may be overcome with antidotes •Low gastric pH inactivates some drugs •MOST COMPLICATED DRUG ABSORPTION ROUTE
Oral Preparations: Enteric coated
- Chemical coating that protects drug from stomach acid
- Drug dissolves in the intestine (less acidic)
- Useful for drugs that are acid unstable
Extended-Release Preparations
- Drugs contain special coatings or ingredients that control drug release
- Allows slow absorption
- Prolonged duration of action
- Can be dosed less frequently
- Improves patient compliance
- Useful for drugs with short half-lives
Sublingual/Buccal Administration
•Drug diffused directly into systemic circulation
Sublingual/Buccal Administration advantages
- Bypasses gastrointestinal (GI) environment
- Ease of administration
- Rapid absorption
Parenteral Administration
•Drug introduced directly into systemic circulation
Parenteral Administration advantages
- Useful for drugs poorly absorbed by GI tract
- Useful for patients unable to take oral medications
- Circumstances that require rapid onset of action
- Highest drug bioavailability
- Avoids harsh GI environment
- Most control over drug dosage
Parenteral Administration Disadvantages
- Irreversible
- Causes pain and fear
- Local tissue damage
- Potential for infections
Routes of Administration (Parenteral)
- Intravenous (IV)
- Intramuscular (IM)
- Subcutaneous (SC)
Intravenous (IV)
- Administration into a vein
- Most common parenteral route
- For drugs not absorbed orally
- Rapid effect
- Maximum control of drug dose
Intravenous (IV) Disadvantages
- Potential for infection
- Hemolysis
- No drug recall
- Cause adverse drug reaction
Intramuscular (IM)
•Administration into a muscle •Aqueous solutions -Absorbed rapidly •Specialized depot preparations -Suspension of drug in nonaqueous vehicle (polyethylene glycol) -Absorbed slowly
Subcutaneous (SC)
•Administration in the subcutaneous tissue of the skin •Absorption via diffusion •Slower drug onset than IV route •Provides constant, slow, sustained effects
Oral/Nasal Inhalation
- Administration via the airways and lungs
- Rapid delivery of drug
- Gases and aerosolized drugs
- Convenient for patients with respiratory disorders
- Direct drug delivery to site of action
Intrathecal/Intraventricular
- Administration directly into cerebrospinal fluid
- Rapid delivery of drug
- Needed to bypass blood-brain barrier
Topical
- Administration of drug to the skin
* Used when desire a local effect
Transdermal
•Administration of drug via the skin •Achieves systemic circulation of drug •Rate of absorption -Skin -Lipid solubility of drug •Sustained delivery of drug
Rectal
- Administration via the rectum
- Prevents destruction of drug by stomach acid
- Ideal if drug causes vomiting
Rectal Disadvantages
- Drug absorption is erratic and variable
- Irritate rectum
- Not a well accepted route
