Principles of drug administration

1. Principles of Drug Administration
&
Routs of drug administration
Dr. S. Parasuraman
Associate Professor, Faculty of Pharmacy,
AIMST University, Malaysia.
Introduction to Pharmacology - for allied health sciences

2. Introduction
• Pharmacology is the science of drugs (Greek:
Pharmacon—drug; logos—discourse in)
• Pharmacology deals with interaction of exogenously
administered chemical molecules with living systems,
or any single chemical substance which can produce a
biological response is a ‘drug’.
• The two main divisions of pharmacology are
pharmacodynamics and pharmacokinetics.
• Pharmacology as an experimental science was
ushered by Rudolf Buchheim who founded the first
institute of pharmacology in 1847 in Germany.
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3. Drug
• The WHO (1966) has given a more comprehensive
definition—
“Drug is any substance or product that is used or is
intended to be used to modify or explore physiological
systems or pathological states for the benefit of the
recipient.”
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4. Principles of Drug Administration
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5. Principles of Drug Administration
• The primary role of the nurse in drug administration
is to ensure that prescribed medications are delivered
in a safe manner.
• RESPONSIBILITIES OF THE NURSE
– Medication knowledge and understanding
– The rights of drug administration
– Patient compliance and successful pharmacotherapy
– Drug orders and time schedules
– Systems of measurement
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6. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• Medication knowledge and understanding
– The nurse’s responsibilities include knowledge and
understanding of the following:
• What drug is ordered.
• Name (generic and trade) and drug classification.
• Intended or proposed use.
• Effects on the body.
• Contraindications.
• Special considerations (e.g., how age, weight, body fat distribution, and individual
pathophysiological states affect pharmacotherapeutic response).
• Side effects.
• Why the medication has been prescribed for this particular patient.
• How the medication is supplied by the pharmacy.
• How the medication is to be administered, including dosage ranges.
• What nursing process considerations related to the medication apply to this
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7. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• The Rights of drug administration
– The traditional five rights of drug administration form the
operational basis for the safe delivery of medications
1. Right patient.
2. Right medication.
3. Right dose.
4. Right route of administration.
5. Right time of delivery.
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8. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• The Rights of drug administration
– The three checks of drug administration that the nurse
uses in conjunction with the five rights help to ensure
patient safety and drug effectiveness.
• Checking the drug with the medication information system
when removing it from the medication drawer,
refrigerator, or controlled substance locker.
• Checking the drug when preparing it, pouring it, taking it
out of the unit-dose container.
• Checking the drug before administering it to the patient.
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9. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• Patient compliance and successful pharmacotherapy
• Compliance or adherence to drug regimen is a major
factor affecting pharmacotherapeutic success.
• Patient noncompliance ranges from not taking the
medication at all to taking it at the wrong time or in
the wrong manner. Adverse effects often prompt
noncompliance.
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10. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• Drug orders and time schedules
• Health care providers use accepted abbreviations to
communicate the directions and times for drug
administration.
• Common abbreviations are given in Annexure -1.
• The nurse makes judgments, based on patient
assessment, as to when such a medication is to be
administered.
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11. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• Systems of measurement
• Three systems of measurement are used in
pharmacology: metric, apothecary, and household.
• Metric system of measurement is most commonly
used.
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12. Principles of Drug Administration
• RESPONSIBILITIES OF THE NURSE
• Systems of measurement
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13. Routs of drug administration
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14. Routs of drug administration
• Most drugs can be administered by a variety of
routes.
• The choice of appropriate route in a given situation
depends both on drug (for example, water or lipid
solubility, ionization), therapeutic objectives (for
example, the desirability of a rapid onset, the need
for long-term treatment, or restriction of delivery to a
local site) as well as patient related factors.
• Major routes of drug administration include enteral,
parenteral, and topical, among others.
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15. Routs of drug
administration
For local action
Topical
Deeper tissues
Arterial supply
For systemic
action
Oral
(Enteral)
Sublingual or buccal
(Enteral)
Cutaneous
Inhalation
Nasal
Parenteral
Subcutaneous (s.c.)
Intramuscular (i.m.)
Intravenous (i.v.)
Intradermal injection
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16. Routs of drug administration - Local
• Topical Drug Administration
– Topical drugs are those applied locally to the skin
or the membranous linings of the eye, ear, nose,
respiratory tract, urinary tract, vagina, and rectum.
– These applications include the following:
• Dermatologic preparations
• Instillations and irrigations
• Inhalations
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17. Routs of drug administration - Local
• Topical Drug Administration
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18. Routs of drug administration - Oral
• Oral ingestion is the oldest and commonest mode of
drug administration.
• Oral drugs are easily self-administered, and toxicities
and/or overdose of oral drugs may be overcome with
antidotes, such as activated charcoal.
• Limitations of oral route of administration
– Action of drugs is slower and thus not suitable for
emergencies.
– Unpalatable drugs are difficult to administer.
– May cause nausea and vomiting.
– Cannot be used for uncooperative/unconscious patient.
– Absorption of drugs may be variable.
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19. Routs of drug administration - Sublingual or
buccal
• For sublingual and buccal administration, the tablet is
not swallowed but kept in the mouth. The mucosa of
the oral cavity contains a rich blood supply that
provides an excellent absorptive surface for certain
drugs.
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20. Routs of drug administration - Inhalation
• Volatile liquids and gases are given by inhalation for
systemic action, e.g. general anaesthetics.
• Absorption takes place from the vast surface of
alveoli - action is very rapid.
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21. Routs of drug administration - Parenteral
• The parenteral route introduces drugs directly into
the systemic circulation.
• Parenteral administration is used for drugs that are
poorly absorbed from the GI tract (for example,
heparin) or unstable in the GI tract (for example,
insulin).
• parenteral routes have the highest bioavailability and
are not subject to first-pass metabolism.
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22. Routs of drug administration - Parenteral
• Parenteral
– Subcutaneous (s.c.): Only small volumes can be injected
s.c. Self-injection is possible because deep penetration is
not needed. This route should be avoided in shock patients.
– Intramuscular (i.m.): The drug is injected in one of the
large skeletal muscles—deltoid, triceps, gluteus maximus,
rectus femoris, etc.
– Intravenous (i.v.): The drug is injected as a bolus or infused
slowly over hours in one of the superficial veins. The drug
reaches directly into the blood stream and effects are
produced immediately (great value in emergency)
(bioavailability is 100%).
– Intradermal injection: The drug is injected into the skin
raising a bleb (e.g. BCG vaccine, sensitivity testing). This
route is employed for specific purposes only.
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23. Routs of drug administration - Parenteral
• Parenteral
– Subcutaneous (s.c.):
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24. Routs of drug administration - Parenteral
• Parenteral
– Intramuscular (i.m.):
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25. Routs of drug administration - Parenteral
• Parenteral
– Intravenous (i.v.):
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26. Routs of drug administration - Parenteral
• Parenteral
– Intradermal injection:
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27. Reference:
• Adams MP. Pharmacology for Nurses: a Pathophysiologic
Approach Fourth Edition. Pearson; 2014.
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28. Abbreviation Meaning
ac before meals
ad lib as desired/as directed
AM morning
bid twice a day
cap capsule
gtt drop
h or hr hour
IM intramuscular
IV intravenous
no number
pc after meals; after eating
PO by mouth
PM afternoon
PRN when needed/necessary
qid four times per day
q2h every 2 hours (even or when first given)
q4h every 4 hours (even)
q6h every 6 hours (even)
q8h every 8 hours (even)
q12h every 12 hours
Rx take
STAT immediately; at once
tab tablet
tid three times a day
Annexure -1:
Drug Administration
Abbreviations Table
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