7. Routes Of Drug Administration

Helpful Slides for students in Pharmacy

1. Routes of DRug
ADministRAtion

HEMED S. HEMEDHEMED S. HEMED
Royal School Of PharmacyRoyal School Of Pharmacy
Dar es salaamDar es salaam
TanzaniaTanzania
What'sapp: [phone]What'sapp: [phone]
20172017

2. Students Learning Tasks
By the end of this session students are
expected to be able to:
Define route of drug administration
Mention major routes of drug administration
Explain advantages and disadvantages of each
route of drug administration
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3. Route of Drug Administration Route of Drug Administration
•A route of drug administration is the path by
which a drug is brought into contact with the
human body.
•The choice of which route of drug
administration to be used depends on two
factors which are:
•The existing preparations of the drug
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4. cont..
•The state of the patient: Emergency or the
impossibility of intake to some routes
•When administering a drug, ensure that the
pharmaceutical preparation is appropriate
for the route specified
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5. Major Routes of Drug Major Routes of Drug
Administration Administration
There are four major routes of drug
administration which are commonly used:
Enteral route
Oral route
Sublingual route
Buccal route
Rectal route
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6. Cont.…
Parenteral route
Intradermal
Subcutaneous route
Intramuscular route
Intravenous injections
Topical route
Inhalation route
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7. Advantages and Disadvantages of Advantages and Disadvantages of
each Route of Administration each Route of Administration
Enteral Route
*1.Oral route: The mouth is commonly used
route for administering drugs.
Advantage of oral route administration
Most convenient
Usually least expensive- cheaper to
manufacture
Safe, does not break the skin barrier
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8. cont..
The gastrointestinal tract provides a huge
surface area for absorption.
The drug can be taken at home by a patient.
Portable.
No pain, easy to take.
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9. Disadvantage of oral route Disadvantage of oral route
administrationadministration
Absorption can be variable and depends on the
chemical nature of the drug, e.g. its ionization,
solubility and stability
Absorption can also depend on the stomach
contents. For example the absorption of
tetracycline antibiotics is inhibited in the
presence of milk.
Drugs may affect gastric emptying and this
may affect absorption.
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10. Cont.….
Inappropriate for patient with nausea and
vomiting
Drug may have unpleasant taste and odor
Inappropriate if patient cannot swallow or is
unconscious (limited uses)
Drug may discolor teeth, harm teeth enamel.
Example hydrochloric acid. Drug may irritate
gastric mucosa
Some of the drug may be partially absorbed or
destroyed by the gastric juices example insulin
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11. *1a.Sublingual route
The medication is placed under the tongue
and allowed to dissolve slowly.
Because of the reach blood supply in this
region it results into rapid onset of the
action.
The patient is instructed not to move the
drug with the tongue nor to eat or drink
anything until the medication has
completely dissolved
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12. Advantage and disadvantages of
sublingual route administration
Same as oral route, plus
Drug can be administered for the local effects
More potent than oral because the drug directly
enter the circulation and bypasses the liver
Disadvantage of sublingual route administration
If swallowed drug may be inactivated by gastric
juice
Drug must remain under the tongue until dissolved
and absorbed
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13. *2.Buccal route
The tablet or capsule is placed in the oral
cavity between the gum and the cheek.
The client is instructed not to manipulate the
medication with the tongue; otherwise, it could
get displaced to the lingual area where it will
be more rapidly absorbed, or to the back of the
throat, where it could be swallowed.
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14. Advantages and disadvantages of
Buccal route
Advantage of buccal route administration
Same as sublingual route
Disadvantage of buccal route
administration
The same as sublingual plus
Dose absorbed is unpredictable
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15. *3.Rectal Route
This means the drugs passed through the
rectum.
Rectal drugs are normally in suppository
form, although a few laxatives and
diagnostic agent are given via enema.
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16. Advantage of rectal route
Favor the drugs which has offensive taste or odor,
or when it can be changed by digestive enzymes.
Drug released at slow steady rate.
It avoids irritation of the upper GIT.
Is convenient and safe method of giving drugs
when the oral method is unsuitable, as when the
patient is unconscious
Venous blood from the rectum doesn’t pass to the
liver thus no first pass effects
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17. Disadvantage of rectal route
Absorption is slower than other routes
It is irregularly and uncompleted absorption
Causes irritation to the rectum
Inconvenient to administer
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18. *Inhalation Route
Inhalation is the breathing of air vapor or volatile
drugs into the lungs.
The gaseous drugs are inhaled and absorbed
through epithelium of the alveoli of the lungs.
Drug administered through this route may be for
the local or systemic effects.
Examples of the drug given by inhalation for
systemic effects are volatile anesthetics agents
such as ether, and halothane E.g. of local
inhalation is nitrate which relieve pain due to
angina pectoris
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19. Advantage of Inhalation route
Acts very quickly because the lungs have a
larger surface area for absorption and they are
reach supplied with blood.
Drug act at the site of action .e.g. pulmonary
diseases.
Introduces drug throughout respiratory tract
Can be used to unconscious client
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20. Disadvantage of inhalation route
Poor regulation of dosage
Inconvenience
Drug intended for localized effect can have
systemic effects
Of use only for respiratory system
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21. *Topical Route
This means application of drug locally at an
intended site such as skin, eye, ear or nose.
Smoothing and softening the dry and rough
areas of the skin.
To provide antiseptic or bacteriostatic effects
in order to inhibit the growth and
multiplication of micro organism
To provide a cleansing effects for the removal
of dirt dermis or infected tissue
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22. Advantages and disadvantages of
topical application
Advantage of topical applications
Provide a local effect
Few side effects
Disadvantage of topical route
Drug can enter body through abrasions and
cause systemic effects
May soil clothes
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23. Parenteral RouteParenteral Route
•The term parenteral “refer to method of drug
administration other than oral and topical
•It is commonly used to indicate the
administration of drugs by “Injections”
•The common types of injections includes,
intradermal, subcutaneous, intramuscular and
intravenous
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24. Parenteral route cont..
•Drugs given parenterally must be sterile, readily
soluble, absorbable, and non-irritating.
•Sterile aseptic technique must be used to avoid
infection.
•Accurate drug dosage, proper rate of injection and
proper site of injection are essential to avoid harm
such as tissue injuries.
•An injected drug is irretrievable, and an error in
dosage or method or site of injection is not easy
corrected.
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25. Intradermal
–Injection is made in the upper layer of the skin
to the dermis
–The amount of drug given is small and
absorption is slow.
–Common method used for allergy testing.
–The injections are best made with a fine, short
needle (26 gauge) and a small barrel syringe
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26. Advantage and disadvantages of
intradermal route of administration
Advantage of intradermal route of
administration
Absorption is slow (this is an advantage in
testing for allergies).
Disadvantage of intradermal route
Amount of drug administered must be small
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27. Subcutaneous route
Small amount of drug in solution are given
subcutaneously (hypodermically)
The needle is inserted through the skin with
quick movement, but the injection is made
slowly and steadily.
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28. Advantage and disadvantages of
subcutaneous route
Advantage of subcutaneous route
Onset of drug action is faster than oral route
Disadvantage of subcutaneous route
Involve sterile technique
More expensive than oral
Only small volume of drug can be
administered
Some drugs can irritate tissue and cause pain.
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29. Intramuscular route
Injections are made through the skin and
subcutaneous tissue into the muscular tissue.
Muscle tissue has a rich blood supply,
medication moves quickly into blood vessels
to produce more rapid onset of action than oral
The anatomical structure of the muscle permits
this tissue to receive a larger volume of
medication. e.g. deltoid and biceps muscle
should receive a maximum of 3ml
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30. Advantage of intramuscular
injection
Pain from irritating drug is minimized.
Can administer larger volume than
subcutaneous
This injection is technically easier than IV.
The gastrointestinal tract and first pass
metabolism are avoided
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31. Disadvantage intramuscular
injections
Break skin barrier
Can produce anxiety
Injections can be painful.
Self administration is difficult.
Rarely, abscesses can form at the site of
injection.
The needle may puncture a small blood vessel
and cause bruising of the skin.
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32. Intravenous injections (IV)
Medications and fluids are administered
directly into the blood stream and immediately
available for use by the body.
The IV route is used when a very rapid onset
of action is desired.
It requires skill and sterile asepsis, and the
drug must be highly soluble and capable of
withstanding sterilization.
IV route is of great value in emergencies.
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33. Advantage of IV routes
A rapid onset of action
The entire injected dose is almost instantly
available, since it bypasses the gastrointestinal
tract and first pass metabolism.
A lower dose is administered than if the drug
is given orally.
Administration is useful for drugs that are
irritant when administered intramuscularly
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34. Disadvantage of IV routes
Break skin barrier
Limited to highly soluble drugs
Drug distribution inhibited by poor circulations
The drug has to be administered by trained
person.
Involuntary injection into an artery can cause
arterial spasm with resulting tissue damage.
Accidental overdose can have serious
consequences.
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35. Key Points
A route of drug administration is the path by
which a drug is brought into contact with the
human body.
The choice of which route of drug administration
to be used depends on two factors
 There are four major routes of drug
administration which are commonly used. These
are enteral, inhalation, parenteral and topical
routes
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