Routes of administration

Question 1

How do you choose the appropriate route of administration?

Answer 1

Site of infection
Which microorganism is responsible
Susceptibility of micro-organism
Pharmacokinetic limitations of the drug 
Status of the patient (emergency treatment, compliant, pre-existing disease / medications)

Question 2

Disadvantage of neomycin sulphate

Answer 2

Poorly absorbed on oral administration

Drug limited to GI Tract

Question 3

Intrathecal injection

Answer 3

Injection into sub-arachnoid space in spinal column

- solution/suspension

Question 4

Advantage of Intrathecal route

Answer 4

Bypasses BBB (blood-brain barrier)
Direct access to CNS

Question 5

Disadvantage of Intrathecal

Answer 5

Requires technically skilled staff
Not suitable for many drugs or additives to formulations
Sterility is essential

Question 6

Where are most drugs absorbed

Answer 6

Small intestines (duodenum)

Question 7

What does passive diffusion depend on

Answer 7

Lipophilicity

Question 8

What limits bioavailability of orally-delivered drugs

Answer 8

First-pass metabolism

Question 9

What form for drug to be absorbed

Answer 9

Uncharged

Question 10

What formulation is used for rectal administration?

Answer 10

Suppositories (solutions, suspensions, solid)

Question 11

Advantage of rectal route

Answer 11

Avoids first-pass metabolism
Avoids oral route problems (vomiting, GI disease)
Useful in patients who struggle with oral route (children)

Question 12

Disadvantage of rectal route

Answer 12

Lower bioavailability compared to oral route

Question 13

Intraveous injection

Answer 13

Injection into vein

Question 14

Subcutaneous injection

Answer 14

Injection into adipose tissue

Question 15

Intramuscular injection

Answer 15

Injection into muscle parenchyma