Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/75

Click to flip

75 Cards in this Set

  • Front
  • Back
Pharmacology
Study of drugs, interactions with living systems,
understanding physical,
chemical properties,
effects in the body,
use of drugs, understanding how drugs are absorbed, distributed, metabolized and excreted.
Clinical Pharmacology
Study of drugs in humans, in patients and healthy people.

Mostly therapeutics, to prevent and treat.
Therapuetics (Pharmacotherapeutics)
use of drugs to diagnose, prevent or treat disease, medical use
Chemical name
chemical description; complex, not commonly used
Generic name
Non-proprietary name, given by United States Adopted Name Council.

Each drug only has one generic name, most commonly used (ex: ibuprofen)
Trade name
Proprietary name, created by drug companies, name approved by the FDA (must be).

Fillers and other ingredients added to them. (ex: ibuprofen- advil, motrin). May affect how people react to them
Effectiveness
elicits the intended response



Major Properties of an Ideal Drug
Safety
Does not produce harmful effects. Impossible to avoid, may be minor. Always a risk.

Major Properties of an Ideal Drug
Selectivity
Produces only the response for which it is given.


Major Properties of an Ideal Drug
Therapeutic Objective
Provide maximum benefit with minimal harm. Benefits outweigh risks.
Administration
-drug dosage (strength),

-route of administration

-timing of administration

(Factors Determining the Intensity of Drug Responses)
Pharmacokinetics
how the body affects the drug

- processes:
absorption, distribution, metabolism & excretion

(Factors Determining the Intensity of Drug Responses)
Pharmacodynamics
how the drug affects the body

processes involve drug-receptor binding followed by the events that lead to the response.

(Factors Determining the Intensity of Drug Responses)
Individual Variation
- physiological factors- weight, age,gender

-pathophysiology- any chronic illness, esp. liver diseases; kidneys (b/c of excretion

- genetic factors- can alter metabolism

(Factors Determining the Intensity of Drug Responses)
Direct penetration
crosses membrane by penetrating through it.

-Lipid soluble only.

-Most common method
Transport systems
-carry the drug across membrane.

-Selective, carry only specific drugs

-Most common: P-glycoprotein - transports drugs out of cells (liver, brain, kidney)
Passage through channels & pores
-very small to pass through

-Rare b/c most need transport or direct penetration
Absorption
-mov’t of the drug from its site of administration into blood.
Distribution
-drug mov’t from blood to interstitial space of tissue into the cells.
Metabolism
- enzymatic processes that alter the drug (biotransformation)

-Occurs in the liver – the hepatic microsomal enzyme system. P450 system
Excretion
- movement of drug and metabolites out of the body

The removal of drugs from the body, primarily through kidneys.

When kidneys not functioning, drug levels are increased. Dosages have to be lowered.
Bioavailability
- extent to which a drug is absorbed and transported to the target tissue.

-Defines extent to which drug is absorbed and transported to tissue
Factors affecting drug absorption
- rate of dissolution
- surface area
- blood flow
- lipid solubility
- pH partitioning
- site of absorption
rate of dissolution
- how easily drug dissolves. Dissolves easy = quicker absorption
surface area
-the larger the surface area the quicker the drug will be absorbed.

Ex: PO meds (usually absorbed in small intestine
blood flow
- absorbed quicker from sites with high blood flow
lipid solubility
-drugs with high lipid solubility are absorbed quicker b/c can penetrate quicker
pH partitioning
difference in pH of plasma/blood & pH at site of admin, greater the difference the more easily absorbed b/c tries to balance difference
site of absorption
-absorption vary depending on the site of admin, route
Routes of Administration
-intramuscular

-intravenous

-subcutaneous

-oral/PO
Influences on absorption
1.food or delayed gastric emptying

2.drug interactions- some meds taken together impair absorption

3.coating

4.solubility of the drug, pH
intravenous
administered directly into blood stream no membrane to cross

advantages: rapid onset, tight control over drug levels, can use large amount of fluid to make less harmful to veins or toxic to body. Some meds harmful to take PO

disadvantages: dangerous – too fast, can’t take it back, inc risk of infection, cost.
intramuscular
injection into muscle, easily absorbed
-alternative route for IV meds- some meds don’t dissolve

-depot preps- give large amount of med into muscle and absorbed slowly over time

advantages: used for meds that don't dissolve well, depot prep

disadvantages: painful, damage to local tissue, nerve damage.
subcutaneous
injection into subcutaneous tissue.

Smaller needle. Technique different for different thickness of skin.

Same advantages and disadvantages as IM.

Morpine can be given IM or subcutaneous
oral/PO
absorbed in the stomach or the intestine

advantages: convenient, easier to use, less expensive.

disadvantages:
-inactivation or destruction of drug,
-GI irritation,
-absorption variable from pt to pt.

-not all meds can be given PO (ex- insulin gets deactivated in stomach)
tablets
-mixture of drug plus binders & fillers.

-Different manufacturers have different binders & fillers
enteric-coated preparations
-coated so will dissolve in intestines but not stomach.

-the coating protects drug or protect the stomach.

PROBLEM- absorption is variable; those with delayed gastric emptying;
sometimes are not absorbed at all
sustained release preparations
-capsules filled with coated spheres that contain the drug.

- Coatings dissolve at variable rates ensures release of drugs all day, take once

PROBLEM- expense
other formulations
- applied to the skin, eyes, nose, ears, vaginally, rectally, inhalation, bronchodilators
blood flow to the tissues
Drugs delivered by blood stream & rate of delivery determined by blood flow to tissue.

More blood flow, more distribution
ability of drug to exit vascular system
exit at the capillary beds, easily pass between capillary cells EXCEPT at:

-blood/brain barrier

-placenta

-protein binding
blood brain barrier
protects the brain from toxic substances

- tight junctions between the capillary cells so through the cells – lipid soluble, med with transport system

BUT can be hard to treat CNS infection (can put reservoir right into brain)
placenta
protective barrier. Lipid soluble can pass thru barrier.

DANGER: can cause detrimental affects to fetus
protein binding
most common albumin, which can’t pass through capillary walls & stays in bloodstream.

If known that drug binds to protein, not given PO, given IV instead
ability of drug to enter cells
lipid solubility and the presence of a transport system.

Some drugs do not cross cell membrane – bind with receptors on cells and can enter
Effects of Drug Metabolism
- accelerated renal drug excretion

-drug inactivation

-increase therapeutic action

-activation of drugs

-increase or decrease toxicity
accelerated renal drug excretion
unable to excrete lipid soluble drugs
metabolism converts lipid soluble drugs into compounds easier to excrete.
drug inactivation
convert active compounds to inactive forms/component

example- anesthesia
increase therapeutic action
increase effectiveness of some drugs by converting into more active form.

Example- codeine
activation of drugs
inactive compound (prodrug) into an active form
increase or decrease toxicity
Decrease in toxicity occur when drug converted into inactive form.
Increase occur when drugs transformed into toxic substances.
Factors that influence Metabolism
- age

- induction of drug metabolizing enzymes

- first-pass effect

- poor nutrition

- drug competition
age
- infants sensitive to drugs until liver matures (age one)
induction of drug metabolizing
enzymes
-increase drug metabolism:

+drugs cause liver to produce drug-metabolizing enzymes through induction.

Induction increase metabolism of drugs -> inc doses needed to maintain therapeutic levels.
first-pass effect
rapid hepatic inactivation of a drug.

To prevent use other routes than PO, because drug can be metabolized by liver immediately and become ineffective
poor nutrtition
Cofactors needed for metabolism
drug competition
compete w/ each other for metabolism if use same metabolic pathway

->dec rate of metabolism, drugs can accumulate and become toxic
Steps in Drug Excretion
- GLOMERULAR FILTRATION

- PASSIVE TUBULAR REABSORPTION

- ACTIVE TUBULAR SECRETION
GLOMERULAR FILTRATION
All drugs except those bound to albumin are filtered through the glomerular membrane.
PASSIVE TUBULAR REABSORPTION
lipid-soluble drugs reabsorbed into blood –not excreted.
ACTIVE TUBULAR SECRETION
Active transport systems pump drugs from blood into the urine for excretion.

example P-glycoprotein, pumps for organic acids/bases
Factors that Affect
Renal Drug Excretion
- PH DEPENDENT IONIZATION

-COMPETITION FOR ACTIVE TUBULAR TRANSPORT

- AGE
PH DEPENDENT IONIZATION
can speed up excretion of drugs by changing pH of the urine we can speed up excretion; causes ionization of drugs
COMPETITION FOR ACTIVE
TUBULAR TRANSPORT
competition can delay excretion and prolong the effects of the drug
AGE
infants’ kidneys not fully developed.

Elderly- decline in renal function, renal excretion declines
Plasma Drug Levels
monitored to regulate drug responses. Adjust up or down

- therapeutic range

-MEC

-toxic concentration
THERAPEUTIC RANGE
between minimum effect concentration & toxic concentration

This is where we see desired drug affect.

Some drugs have small therapeutic range and have to monitor
MEC
minimum concentration that is effective – anything below it is not effective
Toxic concentration
- toxicity occurs
Half-Life
time required for amount of drug in body to decrease by 50%.

Drugs with short half-lives = excreted quickly. Means dosing interval would be short

Drugs with long half-lives = excreted more slowly. Means take less often or smaller doses
Drug Dosing – Time course
- single dosing

- multiple dosing
Single Dosing
plasma levels of drug in plasma go up as drug is absorbed.

Go up to therapeutic level and then goes down. Depends on metabolism and absorption

Drug therapeutic at MEC then it will be therapeutic.

Plasma levels decrease when metabolized and excreted.
Multiple Dosing
accumulation of drug in the body; stays within therapeutic range
plateau
drug level constant – 4 half lives
peak and trough
- highest concentration, must stay below toxic level)

and

- lowest point, check before give meds).