Routes of drug administration

Question 1

How are drugs administered?

Answer 1

Drugs can be administered in a variety of ways in order to reach their targets in the CNS and cause an effect.

Question 2

What is the preferred method of administration?

Answer 2

Oral - through the GI tract

Question 3

What are the different types of oral administration?

Answer 3

• Swallowing (tablets, capsules, drop) to stomach and intestine
• Sublingual - under the tongue so diffuse into blood tissues
• Sublabial - between cheek and gums

Question 4

Why is oral preferred?

Answer 4

Convenient, generally low cost, no need for sterility, patience acceptance

Question 5

List the other methods of administration.

Answer 5

• Rectal (walls of rectum absorb medication quickly and infectively due to highly vascularised mucosal tissue)
• Inhalation - insufflation or lungs
• Intravenous
• Intramuscular
• Subcutaneous
• Topical application
• Direct to CNS - epidural, intracerebral, intracerebroventricular

Question 6

How does this affect pharmacokinetic factors?

Answer 6

Route of administration affects pharmacokinetic factors of absorption, metabolism and elimination by determining amount of absorbing surface, number of membranes needed to cross, amount of drug destroyed and amount of depot binding.