ROUTES OF DRUG presentai ADMINISTRATION 3.ppt

students

1. ROUTES OF DRUG
ADMINISTRATION
Gordon Kibirige
MsCEB, BsHND,PDME,ADPPC,DCM
10/18/24 BsHND 1

2. ROUTES OF DRUG ADMINISTRATION
These are various ways in which drugs are
administered by several different routes as
determined by site of action, rapidity and duration
of effect desired, chemical and physical properties
of the drug.
These include;
Parenteral route
Topical route
Enteral route
Inhalation route
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3. ROUTES OF DRUG ADMINISTRATION
A. Parenteral route
Drugs given by this route are in solution, suspension
and emulsion forms
Parenteral route is the fastest route by which a drug
can be absorbed. It includes;
Intravenous
Intramuscular
Subcutaneous
Intradermal
Intrathecal
Intra-articular
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4. ROUTES OF DRUG ADMINISTRATION
Intravenous injection (IV)
Drugs are injected/administered directly into the
blood stream via a vein where it is distributed in
blood all over the body.
Advantages
 A quick onset of action is achieved
Entire dose of the drug is administered
A lower dose is given compared to oral route
Administration does not irritate the GIT
Large volumes of solutions for replacement therapy
(electrolytes and fluids)BsHND10/18/24 4

5. ROUTES OF DRUG ADMINISTRATION
Disadvantages of IV
Drug has to be administered by a trained person
In case of drug toxicity, retrieval is not possible
It require strict sterility
It is painful
Intramuscular injection (IM)
Drug is injected into one of large skeletal muscles
e.g gluteous, deltoid.
The volume should be kept small (not > 5mls)
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6. ROUTES OF DRUG ADMINISTRATION
Advantages of IM
Drugs that give depot can be given by this route
e.g Benzathine penicillin
It is generally faster than subcutaneous route & oral
Relatively irritating substances may be given IM
It is less painful compared to IV
Disadvantages of IM
Requires trained person to give the drug
Absorption of drug is variable depending on muscle
Some drugs can be painful e.g Benzathine penicillin
Self administration is not possible
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7. ROUTES OF DRUG ADMINISTRATION
Subcutaneous injection (Sc)
Drug is injected into the Sc tissue, the fatty layer
tissue underneath the dermis of the skin.
Commonly used in administering vaccines and
insulin
Provides absorption that is slower than IV route
Advantages of Sc
Can be self administered by patient e.g insulin in
DM patients
Absorption is slower than in IM
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8. ROUTES OF DRUG ADMINISTRATION
Disadvantages of Sc
Can be painful
Irritating drugs may result in severe pain and local
tissue necrosis
Care has to be taken not inject IV
Intracutaneous (I.C)
Injections are given in very small volume (0.1-0.5ml)
Mostly for diagnostic and vaccination
It is given directly into the epidermis just below the
horn layer
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9. ROUTES OF DRUG ADMINISTRATION
Intrathecal (I.T)
Injections are administered into sub arachnoid
space to induce spinal or lumbar anaesthesia.
Only small volumes (1-2ml) after withdrawal of
equivalent volume of C.S.F to avoid increasing the
C.S.F=Intra Cranial Pressure (ICP)
Intra-articular (I.A)
Injections e.g steroids are given into the damaged
irritated joints to control inflammation
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10. ROUTES OF DRUG ADMINISTRATION
Intra-cardial (I.C)
Injections are given directly into the heart using a
central in dwelling catheter introduced by surgical
procedure.
Intraperitoneal (I.P)
Used mainly for renal dialysis solutions
Intra cisternal and peridural
Injections are both difficult procedures because they
involve injection into the duramater and the intra
cranial system of the spinal cord.
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11. ROUTES OF DRUG ADMINISTRATION
Advantages of parenteral routes
Drugs get to site of action more rapidly providing a
rapid response required in emergency.
Dose can be accurately measured & delivered
Can be used when enteral (GIT) is not possible e.g in
coma patients
Suitable for drugs that are not absorbed from the
GIT or are too irritant to be given by other routes.
Disadvantages
Local irritation may occur at site of injection
Rapid absorption can lead to adverse effect
Sterile formulation and aseptic technique neededBsHND10/18/24 11

12. ROUTES OF DRUG ADMINISTRATION
B. ENTERAL ROUTE
Involves drug administration via alimentary tract
This includes; oral, rectal, sublingual & buccal routes
1. Oral route
It is the most convenient and safest route of drug
administration
Drugs given by oral route are in form of tablets,
capsules, syrups, suspension or powders.
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13. ROUTES OF DRUG ADMINISTRATION
Advantages of oral route
It is cheap for the patient, convenient & acceptable
It does not require a skilled person to administer it
Self administration of the drug is possible
Some drugs can only be given by oral route e.g
nifedipine
Incase of drug toxicity, it can be reversed.
Used for local as well as systemic action
Drugs do not require sterile technique for admn
Delivery into circulation is slow so rapid high blood
concn are avoided & adverse effects are less
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14. Diadvantages of oral route
Has delayed action hence not suitable 4
emergencies
Requires patient commitment for compliance
Cant be used by patient in coma
Psychiatric pts and children may refuse the drug
Rate of absorption is variable & irritation of mucosa
surfaces, extensive first-pass metabolism b4 action
Some drugs can be destroyed by GIT enzymes e.g
Insulin, penicillins by HCl acid
It is not suitable for a patient who is vomiting
A higher dose is required compared to parenteral
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15. ROUTES OF DRUG ADMINISTRATION
2. Sublingual (beneath tongue)
The drug usually in form of a tablet, is placed under
tongue & allowed to dissolve slowly e.g Nitroglycerin.
Advantages
Drug is absorbed quickly through oral mucous
membrane into blood stream.
Provides faster therapeutic response than oral route
Effects can be terminated by spitting out the drug
Disadvantages
Inconvenient for frequent use
Irritation of oral mucosa and excessive salivation
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16. ROUTES OF DRUG ADMINISTRATION
3. Rectal route
Drugs are administered via the rectum/anus inform of
suppositories or enema.
Advantages
Provides safe route for vomiting and coma patients
or unable to swallow
Provides an effective route for RX of vomiting &
drugs irritating the stomach e.g Indomethacin
Faster than oral route
No destruction of drugs by GIT enzymes & HCl acid
Drugs may given for local effects e.g HaemorrhoidsBsHND10/18/24 16

17. ROUTES OF DRUG ADMINISTRATION
Disadvantages of rectal route
May be uncomfortable and embarrassing 4 patients
Drugs may result in irregular or incomplete drug
absorption depending on whether faeces are present
May stimulate the patient's vagal nerve by
stretching the anal sphincters
Not suitable if diarrhoea is present
Rectal inflammation may occur with repeated use
Psychological torture especially in adults
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18. C. Miscellaneous Routes
1. Inhalation route
It involves drug administration directly into the
respiratory tract e.g salbutamol inhaler, sodium
chromoglycate is administered by inhalation in
prophylactic Rx of asthma.
Advantages
Drugs in gaseous/aerosol form can be rapidly taken
up or eliminated and Faster action
Disadvantages
Special apparatus needs
Drugs must be non irritant for conscious patients.
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19. ROUTES OF DRUG ADMINISTRATION
2. Topical route
It involves application of drugs over the skin or
mucous membranes to produce local effects.
Advantages
High local concentration can be achieved without
systemic effects
Does not require trained personnel
Disadvantages
Absorption can occur especially when tissue
destruction results into systemic effects.
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20. DRUG NOMENCLATURE
A drug is any chemical substance administered in the
body or biological system that affects the structure or
functioning of a living organism.
Drugs are used for prevention, diagnosis and Rx of
diseases and relive of symptoms
A drug has three main categories of names;
1.Chemical name
2.Generic name
3.Brand name
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21. DRUG NOMENCLATURE
1. Chemical name: It describes the drug’s chemical
composition and molecular structure.
It is not normally used during prescribing because it is
cumbersome.
2. Generic name (non proprietary name): Is the name
approved by a competent drug body e.g USP & BP
It is much simpler than chemical name and is
commonly used in prescribing internationally.
3. Brand name (Trade/proprietary name): Is the
copyrighted name that is given by the company
manufacturing and selling the drug.
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22. Examples of generic & brand names
Generic name Brand name
Amoxicillin Amoxil, Duramox
Propranolol Inderal
Paracetamol Panadol, Kamadol, Cetamol
Salbutamol Ventolin
Chloropheniramine Piriton
Acetyl salicylic acidAsprin
Promethazine Phenergan
Diazepam Valium
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23. Sources of drugs
Drugs can be obtained from any of the following;
Plants e.g digoxin, morphine, quinine
Animals e.g insulin, adrenaline
Microorganisms e.g penicillins, streptomycin
Chemical substances (made from factories) e.g
ampicillin, diazepam
Minerals e.g iron, calcium etc
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24. Classification of drugs
All drugs are restricted i.e should obtained lawfully
from pharmacy, pharmacist, registered medical
practioner. Drugs have special rules for supply,
recording and safe custody. Classifications include;
1.Prescription classification
2.Pharmacological classification
3.According to drug legislation
Prescription classification
In this class drugs are classified basing on whether they
are obtained using prescription (prescription only
medicine/POM) or obtained without prescription
(Over the counter drugs/OTC)
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25. Classification of drugs cont’d
Prescription only medicines/drugs
These drugs can only be obtained when a patient
presents a valid prescription to a pharmacy.
Examples of POM; Amoxicillin, Ciprofloxacin,
Diclofenac, Nifedipine etc
Non prescription drugs/over the counter drugs
These drugs can be obtained either from the
pharmacy or drug shop without prescription
Examples of OTC drugs; Panadol, Hedex, Vitamins,
Action, Good morning syrup, Linctus syrup, ASA etc
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26. Legal classification of drugs
Class A drugs (Opioids/ Narcotics)
Examples: Morphine, Pethedine, Cocaine, CODEINE
They have high abuse potential and acceptable for
medical use.
They may lead to severe physical or psychological
dependence (drugs of addiction)
Class B drugs (Abcs, sulphonamides, antihistamines)
Examples: Phenobarbitone, Diazepam,
Codeine(Limited Opioid Narcotics), Ciprofloxacin,
Amoxicillin, Greseofulvin, Metformin, Vaccines etc
Class C drugs: Over the counter drugs (OTC)
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27. Drug storage
Class A drugs and preparations should be stored in
a separate store/cupboard away from all other
drugs except when in use (Kept under lock & key).
All class B &C shall be kept under the following
conditions
Separate compartments reserved for them/suitable
cupboard and not accessible to anybody except
responsible persons.
The key to cupboard should kept by the in charge
and drugs should be placed in order i.e oral,
injectables, external use separated from each other
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28. Drug storage cont’d
Stability of drugs depends on factors e.g
Temperature, Air, Light, Humidity, Dosage form,
Active ingredients and Manufacturing process.
In general drugs should be stored according to the
manufacturer’s recommendations/instructions.
Most drugs should be stored in a cool, dry place
and out of reach of children.
Some drugs need to be stored in a refrigerator e.g
insulin, vaccines, amphotericin B, cephalosporins
Some drugs are light sensitive therefore should be
kept in a dark placeBsHND10/18/24 28

29. Common abbreviations in Drug admn
od=Once daily
bd=twice daily
tds=three times daily
q.i.d=four times daily
q.h=every hour
p.r.n=when needed
stat=immediately
o.m=each morning
o.n=each night
a.c=before meals
p.c=after meals
p.o= by mouth
iv=intravenous
sc=subcutaneous
Mist=mixture
Inj=injection
Aq=water
Caps=capsules
Tab=tablet
supp=suppository
pess=pessary
Syr=syrup
Ung=ointment
inf=infusion
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30. Common abbreviations in Drug admn
Enem=enema
Gut=drops
g=gram
mg=milligram
ml=milliliter
mcg=microgram
i.m=intramuscular
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