Advantages and disadvantages of drug admission routes

Advantages and disadvantages of drug admission routes

Enteral

Oral= Applied topically to mouth or swallowed for absorption along the gastrointestinal tract

 Advantages-
o Convenient- self administered, pain free, easy to take
o Absorption- takes place along the whole length of the GI tract
o Cheap- compared to most other forms
 Disadvantages-
o Sometimes inefficient- only part of the drug may be absorbed
o First-pass effect- drugs are initially transported to the liver via the portal vein
o Irritation to gastric mucosa- nausea and vomiting
o Destruction of drug by digestive process
o Effect too slow for emergencies
o Unpleasant taste for some
o Unable to use on unconscious patient

Sublingual= Applied under the tongue where it is rapidly absorbed by the sublingual mucosa

 Advantages-
o Economical
o Quick termination
o First-pass effect avoided
o Absorption is quick
 Disadvantages-
o Unpalatable and bitter
o Irritation of oral mucosa
o Large quantities not given
o Few drugs are absorbed

Rectal= Drug is administered into the rectum to be absorbed by the rectum's blood vessels

 Advantages-
o Can be used in unconscious patients and children
o Little or no first-pass effect
o Used in vomiting or where oral administration is not possible
o Faster onset and higher bioavailability
 Disadvantages-
o Inconvenient
o Absorption can be erratic
o Irritation or inflammation of rectal mucosa can occur

Paraenteral

Intravenous= Drug is administered into the vein through a needle