Intro 10.5 - 12 Flashcards
3 ABSORPTION O DRUGS
ROUTES OF ADMINISTRATION (9)
BLOOD FLOW
CONCENTRATION
Drugs usually enter the body remote from the target tissue or organ and require transport by the circulation to the intended site of action
- ROUTES OF ADMINISTRATION (9)
- BLOOD FLOW
- CONCENTRATION
ROUTES OF ADMINISTRATION
BIOAVAILABILITY - amount absorbed into the systemic circulation… amount of drug administered
- ROUTES OF ADMINISTRATION (9)
- BLOOD FLOW
- CONCENTRATION
ROUTES OF ADMINISTRATION (9)
ROUTES OF ADMINISTRATION:
Amount absorbed into the systemic circulation. Amount of drug administered
Bioavailability
ROUTES OF ADMINISTRATION:
when a drug is administered in the blood, it will also be available in our tissues
Bioavailability
ROUTES OF ADMINISTRATION:
The standard is route of administration is
Intravenous
Influences absorption from IM, subcutaneous, and in shock.
- ROUTES OF ADMINISTRATION (9)
- BLOOD FLOW
- CONCENTRATION
BLOOD FLOW
High blood flow maintains a high drug depot-to-blood concentration gradient. Maximizes absorption
- ROUTES OF ADMINISTRATION (9)
- BLOOD FLOW
- CONCENTRATION
Blood Flow
Concentration gradient. Major determinant of the rate of absorption (Fick’s law)
- ROUTES OF ADMINISTRATION (9)
- BLOOD FLOW
- CONCENTRATION
CONCENTRATION
9 ROUTES OF ADMINISTRATION:
O, I, I, S, B&S, R, I, T, T
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
What ROUTES OF ADMINISTRATION:
Maximum convenience
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
ORAL (swallowed)
What ROUTES OF ADMINISTRATION:
Absorption maybe slower, and less complete
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Oral
What ROUTES OF ADMINISTRATION:
Some drugs have low bioavailability when given
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Oral
What ROUTES OF ADMINISTRATION:
Subject to first-pass effect (significant amount of the
agent is metabolized in the gut wall, portal circulation, and liver before it reaches the systemic circulation)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Oral (swallowed)
What ROUTES OF ADMINISTRATION:
it is not 100% bioavailable since it is slower and always passes through the liver. (When the drug passes through the liver, it is metabolized and when the drug goes to the blood circulation, it will be less than 100% of what you administered)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Oral
What ROUTES OF ADMINISTRATION:
Instantaneous and complete absorption
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intravenous (IV) / Parenteral
What ROUTES OF ADMINISTRATION:
Bioavailability by definition is 100%
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intravenous (IV) / Parenteral
What ROUTES OF ADMINISTRATION:
Potentially more dangerous, high blood levels
reached if administration is too rapid
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intravenous (IV) / Parenteral
What ROUTES OF ADMINISTRATION:
Absorption is often faster and more complete (higher bioavailability) than oral
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intramuscular (IM)
What ROUTES OF ADMINISTRATION:
Large volumes (>5 ml into each buttock) if the drug is not irritating
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intramuscular (IM)
What ROUTES OF ADMINISTRATION:
First-pass effect is avoided. (It bypasses the liver however it may cause some bleeding)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intramuscular (IM)
What ROUTES OF ADMINISTRATION:
Heparin cannot be given by this route, causes
bleeding in the muscle
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
INTRAMUSCULAR (IM)
What ROUTES OF ADMINISTRATION:
Heparin cannot be given by this route, causes
bleeding in the muscle. (Muscles are highly vascular tissues, when you inject drug in the muscles, it will be absorbed by the blood vessels surrounding it)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intramuscular (IM)
What ROUTES OF ADMINISTRATION:
Most vaccines are administered through ______ injection
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Intramuscular (IM)
What ROUTES OF ADMINISTRATION:
Slower absorption than IM route
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Subcutaneous
What ROUTES OF ADMINISTRATION:
First-pass effect is avoided
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
- Intramuscular (IM)
- Subcutaneous
- TRANSDERMAL
What ROUTES OF ADMINISTRATION:
Heparin can be given by this route, does not cause
hematoma
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Subcutaneous
What ROUTES OF ADMINISTRATION:
Adipose tissue together with all the other connective tissues are vascular except cartilage
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Subcutaneous
What ROUTES OF ADMINISTRATION:
Insulin are injected with this manner to avoid being recycled by the liver
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Subcutaneous
What ROUTES OF ADMINISTRATION:
Slow or fast depending on formulation of the product. (Nitroglycerin antianginal drugs are pressed under the tongue and the buccal)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Buccal and Sublingual
What ROUTES OF ADMINISTRATION:
Partial avoidance of first-pass effect (not completely as the sublingual route)
—- since the upper part of the rectum still passes through the inferior mesenteric which still passes through the liver however, the lower part of the rectum distal rectum, passes through the internal Iliac veins
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Rectal (suppository)
What ROUTES OF ADMINISTRATION:
This route tend to migrate upward in the rectum where absorption is partially into the portal circulation
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Rectal (suppository)
What ROUTES OF ADMINISTRATION:
Larger amounts of unpleasant drugs are better administered rectally. May cause significant irritation
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Rectal (suppository)
What ROUTES OF ADMINISTRATION:
are used sa mga nagsusuka na mga infants or children
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Rectal (suppository)
What ROUTES OF ADMINISTRATION:
For respiratory diseases. Delivery closest to the target tissue
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Inhalation
What ROUTES OF ADMINISTRATION:
Results into rapid absorption because of the rapid
and thin alveolar surface area
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Inhalation
What ROUTES OF ADMINISTRATION:
Drugs that are gasses at room temperature (eg,
nitrous oxide), or easily volatilized (anesthetics). Yung sa mga nagnenebulize (salbutamol)
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
INHALATION
What ROUTES OF ADMINISTRATION:
Application to the skin or mucous membrane of the eye, nose, throat, airway, or vagina for local effect
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
TOPICAL
What ROUTES OF ADMINISTRATION:
Rate of absorption varies with the area of
application and drug’s formulation
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
Topical
What ROUTES OF ADMINISTRATION:
Absorption is slower compared to other routes
● E.g. antibiotics and antifungal or corticosteroids,
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
TOPICAL
What ROUTES OF ADMINISTRATION:
Application to the skin for systemic effect. Rate of absorption occurs very slowly
- Oral (swallowed)
- Intravenous (IV) / Parenteral
- Intramuscular (IM)
- Subcutaneous
- Buccal and Sublingual
- Rectal (suppository)
- Inhalation
- Topical
- Transdermal
TRANSDERMAL
2 DISTRIBUTION OF DRUGS
DETERMINANTS OF DISTRIBUTION (4)
APPARENT VOLUME OF DISTRIBUTION
4 DETERMINANTS OF DISTRIBUTION
- SIZE OF THE ORGAN
- BLOOD FLOW
- SOLUBILITY
- BINDING
What determinants of distribution?
determines the concentration gradient between blood and the organ. Eg, skeletal muscle and brain
- SIZE OF THE ORGAN
- BLOOD FLOW
- SOLUBILITY
- BINDING
SIZE OF THE ORGAN
What determinants of distribution?
Important determinant of the rate of uptake. Well- perfused organs are Brain, Heart, kidneys, Splanchnic organs
- SIZE OF THE ORGAN
- BLOOD FLOW
- SOLUBILITY
- BINDING
BLOOD FLOW
What determinants of distribution?
If the drug is very soluble in cells, the concentration in the perivascular space will be lower and diffusion from the vessel into the extravascular tissue will be facilitated
- SIZE OF THE ORGAN
- BLOOD FLOW
- SOLUBILITY
- BINDING
SOLUBILITY
What determinants of distribution?
____ of drugs to macromolecules in the blood or tissue compartment will tend to increase the drug’s concentration in that compartment
- SIZE OF THE ORGAN
- BLOOD FLOW
- SOLUBILITY
- BINDING
BINDING
It is the amount of drug in the body to the concentration in
the plasma
APPARENT VOLUME OF DISTRIBUTION. Vd
3 METABOLISM OF DRUGS
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
What Metabolism of Drugs?
Action of many drugs is terminated before they are excreted
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
AS MECHANISM OF TERMINATION OF DRUG ACTION
What Metabolism of Drugs?
Metabolized to biologically inactive derivatives. Conversion to a metabolite is a form of elimination
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
AS MECHANISM OF TERMINATION OF DRUG ACTION
What Metabolism of Drugs?
Inactive as administered and must be metabolized in the body to become active. Eg, levodopa, minoxidil
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
What Metabolism of Drugs?
Many drugs are active as administered and have
active metabolites as well. Some benzodiazepines
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
What Metabolism of Drugs?
Drugs not modified by the body. Continue to act until they are excreted. Eg, lithium
- AS MECHANISM OF TERMINATION OF DRUG ACTION
- AS MECHANISM OF DRUG ACTIVATION (PRODRUGS)
- DRUG ELIMINATION WITHOUT METABOLISM
DRUG ELIMINATION WITHOUT METABOLISM
Determinants of the duration of action for most drugs:
Drug elimination is not the same as drug excretion
- ELIMINATION OF DRUGS
- METABOLISM OF DRUGS
- DISTRIBUTION OF DRUGS
ELIMINATION OF DRUGS
Determinants of the duration of action for most drugs:
A drug maybe eliminated by metabolism long before the modified molecules are excreted from the body
- ELIMINATION OF DRUGS
- METABOLISM OF DRUGS
- DISTRIBUTION OF DRUGS
ELIMINATION OF DRUGS
ELIMINATION OF DRUGS:
excretion is by way of the kidneys (except anesthetic gasses-lungs)
- For most drugs
- For drugs with active metabolites
- For drugs that are not metabolized
- A small number of drugs
For most drugs
ELIMINATION OF DRUGS:
(eg, diazepam), elimination of the parent molecule by metabolism is not synonymous with termination of action
- For most drugs
- For drugs with active metabolites
- For drugs that are not metabolized
- A small number of drugs
For drugs with active metabolites
ELIMINATION OF DRUGS:
excretion is the mode of elimination
- For most drugs
- For drugs with active metabolites
- For drugs that are not metabolized
- A small number of drugs
For drugs that are not metabolized
ELIMINATION OF DRUGS:
combine irreversibly with their receptors, disappearance from the bloodstream is not equivalent to cessation of drug action
- For most drugs
- For drugs with active metabolites
- For drugs that are not metabolized
- A small number of drugs
A small number of drugs
ELIMINATION OF DRUGS:
Very prolonged action. Eg, phenoxybenzamine, irreversible
inhibitor of alpha receptors is eliminated from the bloodstream in 1 h or less after administration, drug’s action lasts for 48 h
- For most drugs
- For drugs with active metabolites
- For drugs that are not metabolized
- A small number of drugs
A small number of drugs
ELIMINATION OF DRUGS:
Rate of elimination is proportionate to the concentration (ie, the higher the concentration, the greater the amount eliminated per unit time)
- First Order Elimination
- Zero OrderElimination
First Order Elimination
ELIMINATION OF DRUGS:
Drug’s concentration in plasma decreases exponentially with time
- First Order Elimination
- Zero OrderElimination
First Order Elimination
ELIMINATION OF DRUGS:
Half-life of elimination is constant regardless of amount of drug in the body
- First Order Elimination
- Zero OrderElimination
First Order Elimination
ELIMINATION OF DRUGS:
Concentration of such drug in the blood will decrease by 50% for every half-life
- First Order Elimination
- Zero OrderElimination
First Order Elimination
ELIMINATION OF DRUGS:
Most common process. Followed by most drugs
- First Order Elimination
- Zero OrderElimination
First Order Elimination
ELIMINATION OF DRUGS:
Rate of elimination is constant regardless of concentration
- First Order Elimination
- Zero OrderElimination
Zero Order Elimination
ELIMINATION OF DRUGS:
Occurs with drugs that saturate their elimination of mechanism at concentrations of clinical interest
- First Order Elimination
- Zero OrderElimination
Zero Order Elimination
ELIMINATION OF DRUGS:
Concentration of such drugs in plasma decrease in
linear fashion over time
- First Order Elimination
- Zero OrderElimination
Zero Order Elimination
ELIMINATION OF DRUGS:
With higher doses, there will be bigger chances of
toxic effect because the patient may not be able to
eliminate it. Eg, alcohol, phenytoin, aspirin
- First Order Elimination
- Zero Order Elimination
Zero Order Elimination