Download Drug Administration Phase

RSPT 2317
Principles of Drug Action - Part 1
RSPT 2317
Principles of Drug Action
Part 1: The Drug Administration Phase
Drug Administration Phase
This phase describes the method by
which a drug dose is made available to
the body.
Definitions
• Drug dosage form:
– the physical state of the drug in association with
nondrug components
• Route of administration
– the portal of entry of the drug into the body
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RSPT 2317
Principles of Drug Action - Part 1
Drug Formulations
and Additives
Drug Formulations & Additives
• A drug is the active ingredient, but not the
only ingredient in a drug formulation
– example: albuterol
• nebulizer solution
•
MDI solution
•
DPI formulation
Drug Formulations & Additives
• Other examples:
– oral forms
– capsules
– time-released capsules
– coated tablets
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RSPT 2317
Principles of Drug Action - Part 1
Routes of Administration
Routes of Administration
• Choice depends on several factors
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–
–
–
–
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systemic or local effect
desired timing of onset & duration of action
stability of drug in gastric or intestinal environments
patient’s ability to swallow or retain oral meds
amount of drug to be given
convenience vs. safety
Routes of Administration
• Enteral
– used for drugs intended for absorption anywhere
along the GI tract
– oral route is most common
– suppositories (rectal)
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RSPT 2317
Principles of Drug Action - Part 1
Routes of Administration
• Enteral
– sublingual
– indwelling gastric tubes
Routes of Administration
• Parenteral
– any route that excludes the GI tract
– most common are the “injectable” routes
• intravenous (IV)
•
intramuscular (IM)
Routes of Administration
• Parenteral
– subcutaneous (SC)
– other parenteral routes include
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RSPT 2317
Principles of Drug Action - Part 1
Routes of Administration
• Transdermal
– applied to the skin, usually in the form of a “patch”
– drug is absorbed
– useful in maintaining
– used for long-term continuous delivery
Routes of Administration
• Inhalation
– used primarily for a localized effect
– this allows for smaller doses and, hopefully, fewer
adverse side effects
• case in point - inhaled steroids vs. oral steroids
• common oral prednisone dose
•
common aerosol fluticasone dose
Routes of Administration
• Inhalation
– devices used to deliver aerosol drugs include
• large volume nebulizers
• small volume nebulizers (SVN, HHN)
• metered dose inhalers (MDI)
• dry powder inhalers (DPI)
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RSPT 2317
Principles of Drug Action - Part 1
Routes of Administration
• Topical
– drugs are applied directly to the skin or mucous
membranes for a local effect
– drugs intended for topical use are usually
formulated to minimize systemic absorption
– examples include:
• cortisone cream for dermatitis
• eye drops to help control glaucoma
• nasal sprays or drops to relieve congestion
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