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D116 STUDY GUIDE 2026 | GRADED A+ |
GUARANTEED PASS!!
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Unit 2: Integrating Principles of Pharmacology
Pharmacokinetics, Pharmacodynamics, and Medication Interactions:
Pharmacokinetics - What your body does to a drug (ADME)
Absorption – the drug’s ability to pass through
barriers such as the intestinal lining, the lungs, or
the skin.
Distribution – how the drug is
distributed
around the body and its propensity
to
accumulate in certain tissues or organs.
Metabolism – how the body breaks down
the
drug, normally by the liver. The key issues
are drug-to-drug interactions, and the
effects
of the metabolites (the new
chemicals
created as a result of metabolism).
Elimination – the rate and process
through
which the drug exits the body.
Properties of Major Routes of Drug Administration
Route Barriers to Barriers to Advantages Disadvantages
Absorption Absorption
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Parenteral
Intravenous None Instantaneous Rapid onset, and Irreversible
(IV) (absorption is hence ideal for
bypassed) emergencies Expensive
Precise control over Inconvenient
drug levels
Difficult to do, and
Permits use of large hence poorly suited
fluid volumes for self-administration
Permits use of irritant Risk for fluid overload,
drugs infection, and
embolism
Drug must be water
soluble
Intramuscular Capillary wall Rapid with Permits use of poorly Permits use of poorly
(IM) (easy to pass) water-soluble soluble drugs soluble drugs
drugs
Permits use of depot Permits use of depot
Slow with preparations preparations
poorly soluble
drugs
Subcutaneous Same as IM Same as IM Same as IM Same as IM
(subQ)
Enteral
Oral (PO) Epithelial lining Slow and Easy Variability
of variable
gastrointestinal Convenient Inactivation of some
tract; capillary drugs by gastric acid
wall Inexpensive and digestive enzymes
Ideal for Possible nausea and
selfmedication vomiting from local
irritation
Potentially reversible,
and hence safer than Patient must be
parenteral routes conscious and
cooperative.
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Drug Movement at Typical Capillary Beds. In most capillary beds, “large” gaps exist between the cells
that compose the capillary wall. Drugs and other molecules can pass freely into and out of the
bloodstream through these gaps. As illustrated, lipid-soluble compounds can also pass directly through
the cells of the capillary wall.
The BBB - Drug Movement Across the Blood-Brain Barrier. Tight junctions between cells that compose
the walls of capillaries in the central nervous system prevent drugs from passing between cells to exit
the vascular system. Consequently, to reach sites of action within the brain, a drug must pass directly
through cells of the capillary wall. To do this, the drug must be lipid soluble or be able to use an existing
transport system.
messages.downloaded_by
D116 STUDY GUIDE 2026 | GRADED A+ |
GUARANTEED PASS!!
, lOMoAR cPSD| 57629747
Unit 2: Integrating Principles of Pharmacology
Pharmacokinetics, Pharmacodynamics, and Medication Interactions:
Pharmacokinetics - What your body does to a drug (ADME)
Absorption – the drug’s ability to pass through
barriers such as the intestinal lining, the lungs, or
the skin.
Distribution – how the drug is
distributed
around the body and its propensity
to
accumulate in certain tissues or organs.
Metabolism – how the body breaks down
the
drug, normally by the liver. The key issues
are drug-to-drug interactions, and the
effects
of the metabolites (the new
chemicals
created as a result of metabolism).
Elimination – the rate and process
through
which the drug exits the body.
Properties of Major Routes of Drug Administration
Route Barriers to Barriers to Advantages Disadvantages
Absorption Absorption
messages.downloaded_by
, lOMoAR cPSD| 57629747
Parenteral
Intravenous None Instantaneous Rapid onset, and Irreversible
(IV) (absorption is hence ideal for
bypassed) emergencies Expensive
Precise control over Inconvenient
drug levels
Difficult to do, and
Permits use of large hence poorly suited
fluid volumes for self-administration
Permits use of irritant Risk for fluid overload,
drugs infection, and
embolism
Drug must be water
soluble
Intramuscular Capillary wall Rapid with Permits use of poorly Permits use of poorly
(IM) (easy to pass) water-soluble soluble drugs soluble drugs
drugs
Permits use of depot Permits use of depot
Slow with preparations preparations
poorly soluble
drugs
Subcutaneous Same as IM Same as IM Same as IM Same as IM
(subQ)
Enteral
Oral (PO) Epithelial lining Slow and Easy Variability
of variable
gastrointestinal Convenient Inactivation of some
tract; capillary drugs by gastric acid
wall Inexpensive and digestive enzymes
Ideal for Possible nausea and
selfmedication vomiting from local
irritation
Potentially reversible,
and hence safer than Patient must be
parenteral routes conscious and
cooperative.
messages.downloaded_by
, lOMoAR cPSD| 57629747
Drug Movement at Typical Capillary Beds. In most capillary beds, “large” gaps exist between the cells
that compose the capillary wall. Drugs and other molecules can pass freely into and out of the
bloodstream through these gaps. As illustrated, lipid-soluble compounds can also pass directly through
the cells of the capillary wall.
The BBB - Drug Movement Across the Blood-Brain Barrier. Tight junctions between cells that compose
the walls of capillaries in the central nervous system prevent drugs from passing between cells to exit
the vascular system. Consequently, to reach sites of action within the brain, a drug must pass directly
through cells of the capillary wall. To do this, the drug must be lipid soluble or be able to use an existing
transport system.
messages.downloaded_by
