Title: Routes of Drug Administration
1Routes of Drug Administration
2Factors Deciding Choice ofRoute
- Type of described effect, systemic or local
- Physiochemical properties, solid or insoluble
- Rapidity of effect
- Quality of effect
- Condition of patient, conscious or unconscious,
vomiting
3Drug Administration
Topical/Local Administration
Systemic Administration
Mucus Membrane
Enteral
Parenteral
Skin
Inhalation
4Systemic Routes
- Enteral through GIT
- Orally
- Buccal or sublingual
- Rectal
- Parental
- Intravenous (IV)
- Intramuscular (IM)
- Subcutaneous (SC)
5Enteral Route
6Oral Administration
- Via mouth
- Tablets, capsules, powder, syrup, mixture
suspension or emulsion
7Advantages of oral route
- Convenience and patient comfort
- Safety, since medication can be retrieved in case
of error or intentional overdose - Economy, since there are few equipment cost
8Disadvantages of oral route
- Slower onset of absorption and action
- Rate and degree of absorption vary with
gastrointestinal contents and motility - Some drugs destroyed by digestive fluids and must
be administered by injection - Cannot be used with nausea or vomiting
- Dangerous to use if patient has dysphagia, due to
the possibility of aspiration
9- Cannot be used for unconscious patients
- Cannot be use for patients who should keep nil by
oral
10Absorption from stomach and upper intestine is
affected by-
- Surface area
- Blood flow to site of absorption
- Physical state solid, solution, suspension
- Water solubility
- Concentration at the site of absorption
- Rate of dissolution
- Rate of disintegration
- Particle size
11Via Nasogastric tube/Gastric tube
- For the patients unable to swallow
- Advantages ability to bypass mouth and pharynx
when necessary , elimination of numerous
injections - Disadvantages discomfort specially for the
conscious patients
12Buccal or sublingual Route
- Buccal medication placed in the pouch between
the cheek and the gum - Sublingual under the tongue
- Advantages directly absorb to the circulation
and rapid action - Disadvantage misunderstanding of the way of use
13Rectal Route
- For the patients having nausea and vomiting or
patients who are unable to swallow - Advantages bypassing the action of digestive
enzymes - Avoidance of irritation to the upper GI tract
14Disadvantages of Rectal route
- Many medications are unavailable in suppository
form - Prolonged use of rectal suppositories can cause
rectal irritation - Absorption may be irregular or incomplete if
feces are present - Inconvenient embarrassing
- Rectal inflammation occurs
15Parenteral Administration
16Parenteral Administration
- Intravenous
- Intramuscular
- Subcutaneous
- Intradermal
- Intrathecal
- Intraarterial
- Intra articular
17Intravenous Route
- Drug administration directly to the vein
- Direct injection
- Bolus
- Infusion
18Advantages of Intravenous Route
- Immediate effects
- Valuable for emergency use
- Suitable for large volume
- Complete bioavailability
19Disadvantages of Intravenous Route
- Not suitable for oily solutions insoluble
substances - Drug administered cannot be withdrawn
- Thrombophlebitis occurs at injection site
- Lack of sterility may cause viral hepatitis
- or AIDS
- Increased risk of adverse drug reactions
- Time and skill required for venipuncture
20- Difficulty of maintaining IV line
- Complications of IV therapy bleeding, infection
and fluid overload
21Intramuscular Route ( IM)
- Injections of drugs into certain muscles
- Usually doses 3ml or less
- IM injection
- Depot preparation
- Absorption depends upon rate of blood flow to the
injection site - Rapid action compared to SC route
- Slow releasing compared to IV route
-
22- Advantages can be use to administer solutions
or suspensions - Slow, sustained effect from depot preparation
- Disadvantages incorrect placement of the needle
may damage blood vessels or nerves - Pain
- Abscess formation
- Avoid during anticoagulant therapy
23Subcutaneous Route (SC)
- Injection of drugs under the skin
- Use for highly soluble, non irritating, small
volume of drug about 1ml or less - Absorption is slower and the drug action is
generally longer with SC injections than with IV
or IM injections - Advantages Slow absorption and distribution
24- Disadvantages tissue damage, tissue necrosis and
sterile abscess formation - Only nonirritant drugs
- Not suitable for large volume
25Intraarterial Route
- Direct injection into artery
- Localization of effect in particular tissue or
organ - Advantages Diagnostics agents
- Disadvantages Reserved route for experts
26Intrathecal Route
- Injections into cerebrospinal fluid
- Blood Brain Barrier Blood CSF Barrier slow drug
entry into CNS - Used when local and rapid effects of drugs on
the meninges or cerebrospinal axis desired
27Intradermal Route
- Injection into skin layers
- Uses BCG, Small pox vaccination
- Testing drug sensitivity- Penicillin's
- Tuberculin test
28Intraarticular Route
- Drug administration directly to the joint
- Usually local effect
- Uses Rheumatology disorders
29Topical Application- MucousMembrane
- Conjunctiva, nasopharynx, oropharynx, vagina,
urethra, urinary bladder, ear, nose, anal canal
for local effects - Ointment, cream, drops, jelly, powder, tablet,
suppository, pessary, sprays, gargles
30Topical Application- Skin
- Absorption depends on surface area of
application, lipid solubility - Few drugs readily penetrate skin
- Burned, denuded, abraded, inflammation increase
systemic absorption - Controlled- release topical patches
31- Advantages Absorption rapid
- Only local effect
- Disadvantages Toxicity by highly lipid soluble
substances
32Inhalation
33Inhalation
- Via inhaler
- Via nebulizer
- Medication directly to the respiratory system
34Advantages of Inhalation
- Rapid action of the drug, with local effects with
in the respiratory tract - Potent drugs may be given in small amounts,
minimizing the side effects - Convenience and comfort of the patient
35Disadvantages of Inhalation
- Requires cooperation of the patient in proper
breathing techniques for effectiveness - Adverse systemic side effects may result rapidly
because of extensive absorption capacity of the
lungs - Improperly administered or too frequently
administered, inhalation can lead to irritation
of the trachea or bronchi or bronchospasm
36- If not clean properly nebulizers can be a source
of infection
37Thank you.