Chapter 3 And 4 Flashcards
First pass
(Inactivation) in liver metabolized and destroyed
Drug is transported directly into the liver via the portal vein
Sublingual and buccal
Faster effects than swallowing the drug (for acute angina)
Rectal
Good for patient who is unconscious or when vomiting prevents drugs from being taken orally
Absorbed poorly or incompletely and irritation of the rectal mucosa
Paraenteral inhilation
Rapid entry into the bloodstream through diffusion into pulmonary circulation ( ex. Inhaler)
Intrathecal
Deliver injection fluid filled space between the thin layers of tissue that cover the brain and spinal cord
(Ex. Spinal subarachnoid space)
Allow certain drugs to bypass the blood brain barrier and reach the CNS
For tendon sheath or bursa to treatment
Iv and intra-arterial
Minimize first pass
Iv injection
Resulting in peak levels instantaneously and reach the target site rapidly
Iv cannula (line) allow prolonged and steady diffusion
Intra arterial injection
Relative difficult and dangerous procedure
Occasionally used in chemo to decrease exposure to healthy tissue
Subcutaneous injection
Relatively slower more prolonged release into the systemic circulation
( local anesthesia, insulin and hormonal contraceptive)
Intra muscular injection
Easily accessible
Realities steady prolonged release
Relatively rapid effect while avoiding large increase of plasma seen within the iv
Intra muscular injection
Easily accessible
Realities steady prolonged release
Relatively rapid effect while avoiding large increase of plasma seen within the iv
Transdermal
Absorbed through the dermal layers and into the subcutaneous tissues or the peripheral circulation
Iontophoresis
Use electrical current to deliver medication into the target tissue
Phonophoresis
Deliver the drug with the aid of ultrasound
Bioavalibility
The extent to which the drug reaches the systemic circulation
Ex. If 100 mg of a drug is given orally and 50 mg eventually make it into the systemic circulation the drug is said to be 50% bioavailable
Lipid soluble compounds
(Including most drugs) are able to pass directly through the membrane by dissolving in the lipid bilayer
Drugs will diffuse more readily through the lipid layer in its what type of state ?
Neutral, non ionized state
A weak base drug is absorbed where ?
In the duodenum it becomes nonionized and lipid soluble allowing it to be absorbed in the small intestine
A weak acid drug is absorbed where?
Gets absorbed in the stomach due to the acidic environment going to its neutral and nonionized form
Characteristic of active transports
Carrier specificity
Expenditure of energy (ATP hydrolysis)
Ability to transport substance against a concentration gradient
Facilitated diffusion
Had the features of both active transport and passive diffusion
An assisting protein carrier is present but no net energy is expended
Ex. Skeletal muscle glucose uptake
Passive diffusion
The driving forces WITHOUT EXPENDING any energy are the electrical (charged particles) chemicals and pressure differences on the two sides of the membrane
Alimentary canal
Enteral administration
Non alimentary routes
Parenteral administration
Diffusion between cell junctions
The primary way that a drug may diffuse across the barrier is by diffusing first into and then out of the other side of the cells compromising the barrier
Exocytosis
A process by which the contents of a cell vacuole are releases to the exterior of the cell membrane
Endocytosis
Taking in matter by a living cell by invagination of its membrane to form a vacoule
( swallows into the cell memebrane)
Factors affecting distribution
Tissue permeability
Blood flow
Binding to plasma proteins (Ex. Albumin)
Only the unbound drug can reach the target tissue and exert an effect
Binding to subcellular components
(Ex. Binding to lysosome)
Volume of distribution
Amount of drug distributed
(divided by )
Concentration of drug in plasma
Drug storage sites
Adipose(primary)
Bone (toxic agents and heavy metals)
Muscles
Organs (kidney and liver)
The use of specific drugs to prevent, treat, or diagnose disease is known as
Pharmacotheraputics
Toxicology
The study of the harmful effects of chemicals
The generic name of the drug
Is also known as the official or nonpropietary name
Is often derived from the chemical name
Tends to be somewhat shorter than the drugs chemical name
The generic form of a drug is considered to be as safe and effective as the original brand name product if the generic form ______ as the brand name
Has the same type and amount of active ingredients
Uses the same administration route
Has the same pharmacokinetics profile (drug absorption, plasma levels, and so forth)
Produces the same therapeutic effects
Regarding drug development and approval an orphan drug is a drug that is
Given special funding for development because it is uses in a small patient population with a relatively rare disease
Prescription use of a drug to treat conditions other than those that the drug was originally approved to treat (off label prescribing)
Is legal and quiet common in the us
When two drugs are compared the drug that requires a lower dosage to produce the same effect as a higher dose of the second drug is said to
Be more potent
The______ effect occurs when drugs are transported initially to the liver where a significant amount of the drug may be metabolized and destroyed before the drug reaches its primary site of action
First pass
The extent to which a drug reaches the systemic circulation is referred to as
Bioavailibility
Osmosis refers to the special case of diffusion where the diffusing substance is
Water
A drug that has a volume of distribution of approximately 42 L in a healthy 70kg man will typically be
Distributed uniformly throughout all of the body fluids
Drug developers are exploring nano technology as a way to
Target deliver drugs to specific tissues within the body
Facilitate drug absorption from the gi tract
Enable drugs to cross the blood brain barrier more easily
Drug metabolism that occurs when a drug is changed chemically following administration is also known as
Biotransformation
Most drugs are metabolized by _____ to the drug molecule and the enzymes that catalyst these reactions are typically located at the_____ of specific cells
Adding or removing a hydrogen; smooth (agranular) endoplasmic reticulum
Prolonged administration of therapeutic drugs and other substances may enhance the livers ability to metabolize certain drugs, thus decreasing their therapeutic effect. The process is known as
Enzyme induction
Drugs and their metabolites are excreted from the body primarily by
Kidneys
To calculate drug elimination rate blood flow to an organ and the function of drug removed from the plasma as it passes thought the organ are measures to determine drug
Clearance
Drug metabolism by the liver and other organs typically creates more ________ compound this enables the compound to be ______when it reaches the nephron in the kidney
Polar;excreted
The acetylcholine receptor located on the postsynaptic membrane of the skeletal neuromuscular junction is an example of a membrane receptor
Function as an ion channel or pore
Some drugs affect the function of the adenylase cycles and enzyme located on the inner surface of the cell membrane. This enzyme is responsible for hydroxyzine adenosine triphoste (ATP) _____ which acts as a second messenger that activates other enzymes
Cyclic adenosine monophosphate
A drug that binds readily to available receptors even if the concentration of drug is relatively low is said to have ______ for that receptor
High affinity
The ability of a drug to bind to its receptor can be influenced by local chemicals such as guanine nucleotides ammonium ions and divalent cations. These local regulators are commonly known as
Allosteric modulator
In constrast to an agonist a pharmacological antagonist
Has affinity for the receptor but lacks efficacy
Is also known as a blocker
Can be used to prevent endogenous chemicals from overstimulating the receptor
A drug that fails to evoke a maximal response even though it occupies all available receptors is known as
A partial agonist
Overstimulating of postsynaptic may lead to a decrease in responsiveness of the receptors. A fairly brief and transient decrease in receptor responsiveness is known as ______ whereas a more prolonged process in which the actual number of available receptors is diminished is known as _______
Desensitization; down regulation
