ROUTES OF DRUG ADMINISTRATION
Most of the drugs can be administered by variety of routes and most appropriate route is
decided on basis of following factors.
Physical and chemical properties of drug
Site of action- localized/generalized
Rate and extend of absorption through each route
Effect of digestive juices and metabolism
Rapidity of the desired response
Accuracy of dosage required
Condition of the patient
Classified into Local routes and Systemic routes
LOCAL ROUTES
Used for localized lesions at accessible sites.
High concentration is attained with minimal side effect and toxicity.
1)Topical – external application of drugs to the surface
Used for lesions on skin, eyes, ear canal, oropharyngeal/ nasal mucosa, anal canal etc.
In form of lotion, ointment, cream, powder, rinse, paints, drop, spray, lozengens,
suppositories etc.
2)Deeper tissue – approached through syringe and needle but systemic absorption is slow.
Example- intra-articular injection, intrathecal injection (lignocaine), retrobulbar injection etc.
3)Arterial supply – close intra-arterial injection used for contrast media in angiography,
anticancer drugs infused in femoral or brachial artery.
SYSTEMIC ROUTES
Absorbed into blood stream and distributed all over through circulation.
Oral
Oldest and commonest mode
Available in both solid (powder, tablet, capsule etc.) and liquid (syrups, emulsions, elixirs
etc.) forms.
Advantages – safe, convenient, painless, non-invasive, no need for assistance and cheaper.
Most of the drugs can be administered by variety of routes and most appropriate route is
decided on basis of following factors.
Physical and chemical properties of drug
Site of action- localized/generalized
Rate and extend of absorption through each route
Effect of digestive juices and metabolism
Rapidity of the desired response
Accuracy of dosage required
Condition of the patient
Classified into Local routes and Systemic routes
LOCAL ROUTES
Used for localized lesions at accessible sites.
High concentration is attained with minimal side effect and toxicity.
1)Topical – external application of drugs to the surface
Used for lesions on skin, eyes, ear canal, oropharyngeal/ nasal mucosa, anal canal etc.
In form of lotion, ointment, cream, powder, rinse, paints, drop, spray, lozengens,
suppositories etc.
2)Deeper tissue – approached through syringe and needle but systemic absorption is slow.
Example- intra-articular injection, intrathecal injection (lignocaine), retrobulbar injection etc.
3)Arterial supply – close intra-arterial injection used for contrast media in angiography,
anticancer drugs infused in femoral or brachial artery.
SYSTEMIC ROUTES
Absorbed into blood stream and distributed all over through circulation.
Oral
Oldest and commonest mode
Available in both solid (powder, tablet, capsule etc.) and liquid (syrups, emulsions, elixirs
etc.) forms.
Advantages – safe, convenient, painless, non-invasive, no need for assistance and cheaper.
