Routes of administration
Introduction: –
Routes of drug administration is the path by which the drug is introduced into
the body for treatment of disease.
Drugs are available in various form like tablet, Capsule
suspension, ointment, Cream, injection etc.
Routes of drug
administration
|
Enteral |
Parenteral |
Topical |
|
Oral |
Intravenous |
|
|
Sublingual |
Intramuscular |
|
|
Rectal |
Subcutaneous |
|
|
|
Inhalational |
|
|
|
Transdermal |
|
1. External
administration: – This route is best for drug administration unless any
specific advantage is desired associated with other delivery route.
a) Oral: – In
this route of administration the drug either liquid or solid preparation is
placed in mouth cavity is swallowed along with drinks such as water, milk etc.
Advantage:-
• Most of
medicinal preparations are consumed orally.
• Economical
chance of acute drug reaction.
• Very convenient
for children and aged people.
Disadvantage:-
• Sometime
inefficient for the patients.
• Irritation to
gastric mucosa.
• Can cause
Nausea& vomiting.
b) Rectal: –
Suppositories/ Enema are drug that are placed in rectal route. Ex-Aspirin,
Theophylline, Chlorpromazine.
Advantage:-
• Useful in the
children/ adult.
• Use in the case
of vomiting.
• Higher
concentration of drug proparty achieved.
Disadvantage:-
• Irritation or
inflammation of Rectal mucosa can occur.
• Absorption is
slow of this route and Erratic.
Sublingual/ Buccal
route
Sublingual: –
This dosage form is placed under the tongue and allow to dissolve in the mouth
cavity. The drug is absorbed by sublingual mucosa.
Buccal route: –
In buccal route drug kept within the mouth around the cheeks or buccal cavity,
where it disintegrates and get absorbed.
Advantage:-
• Rapid absorption
of the drug.
• Drugs do not
undergo first- pass metabolism.
• Portal
circulation is by passed.
• Maintained drug
stability.
• No involvement
of harsh GI environment.
• Less chance of
infection.
Disadvantages:-
• Only small dose
can take.
• Sometime
complete drug is not absorbed.
• Not effective in
emergencies.
• Drug couldn’t be
administered during emesis.
• Unpleasant teste
of drugs.
2. Parenteral
Administration: – The route of administration others than the enteral route
comes under parenteral route. Parenteral Administration is injection or
infusion by means of needle or catheter inserted in the body.
Intravenous (IV)
Route
IV is the route of drug administration in which the drugs
are administered into the veins. Injection are preferred for orally unabsorbed
Drugs like Atracurium (neuromuscular blocker).IV route shows rapid effect the
maintains level of drug in circulation.
Advantage:-
• 100%
bioavailability.
• It this route
shows rapid effect.
• This route is
the best in the case of diarrhea and vomiting.
• Take medicine in
large quantities.
Disadvantage:-
• This route is
less safe than oral route.
• Technical and
trained person required.
• Costly.
• Inconvenient and
painful causing irritation, cellulitis and thrombophlebitis.
Intramuscular: –
In this route the drug is administration into the muscles.
Advantage:-
• Rapid onset of
action.
• No G.I.T.
related factors.
• Mild irritants
can be metabolism.
• The absorption
is reasonably uniform.
Disadvantage:-
• Only 10ml of
drug is given.
• Local pain
cause, Abscess and infection.
• Can cause
nervous damage.
Subcutaneous Route
(SC)
This route of administration the drug gives under the skin.
Example: –
Hormonal drug (Insulin injection) Advantage:-
• Can be easily
self-administering by the patient.
• Complete but slow adsorption.
• Low risk of
systematic infection.
Disadvantage:-
• Maximum 2ml of
drug may be injected.
• Less painful
then the IV /IM route.
• Irritatant drugs
cause tissue damage.
Intara-arterial:-
This route of drug administration the drugs are given into
the arteries. Vasodilator, anticancer drugs are given by skin route.
Advantage:-
• Bioavailability
100%.
• It is of great
clinical value in administering anticancer drugs.
Disadvantage:-
• Only can used in
cancer and vasodilator.
• Painful
• Risky
Inhalation:-
In case of inhalation route drugs are administered either as
Aerosol system in the form of vapors
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