Drug delivery systems

Question 1

what are the three key factors that determine the drug delivery system we use?

Answer 1

The dose of drug to be given
The frequency of administration
The timing of administration

Question 2

what other things should we take into account when choosing a dosage regime?

Answer 2

Recommended dose (BNF / BNFc) 
renal and hepatic function
age and weight 
starting dose and what do we want to increase the dose too?

Question 3

Does oral medication have a systematic or a local affect?

Answer 3

systematic.

Question 4

Where does absorption take place (usually) when the drug is taken orally?

Answer 4

GI tract

Question 5

what does a solution administration allow?

Answer 5

Naso - gastric - good if the patient has swallowing difficulties.

Question 6

What is a suspension?

Answer 6

A dispersion of a course drug particles in a liquid phase.

Question 7

When taking tablets, what determines the rate of reaction?

Answer 7

Dissolution / tablet break down

Question 8

What are enteric coated tablets?

Answer 8

Tablets in which disintegration is delayed until they reach the small intestine.

Question 9

why may a tablet be enteric coated?

Answer 9

1) to protect drug from stomach (omeprazole)

2) to protect stomach from drug (aspirin)

Question 10

Why are prolonged delayed response formulations useful?

Answer 10

their good for disorders that require prolonged therapy.
they maintain drug levels within a therapeutic range
they reduce the need for frequent dosing.

Question 11

How are some prolonged delayed response drugs administered?

Answer 11

orally -
parental
surgical implants - ‘the rod’

Question 12

what does a pro drug depend on?

Answer 12

metabolism to activate it.

Question 13

what are the benefits of using pro drugs?

Answer 13

prolonged duration of action

avoidance of degradation of drug in the gut.

Question 14

what type of drugs is buccal and sublingual administration good for?

Answer 14

drugs that have extensive pre- systematic or first pass metabolism.

Question 15

Does rectal administration provide a local or systematic response?

Answer 15

can do both!

Question 16

Does vaginal administration provide a local or systematic response?

Answer 16

local

Question 17

What are good ways of administering drugs that have a short half life?

Answer 17

IV or injection based.

Question 18

what are some benefits of injection based administration?

Answer 18

it is fast, bypasses first mass metabolism, can be given to unconscious patients.

Question 19

Why might IV medication be given slowly?

Answer 19

to prevent toxic effects.

Question 20

what is good about intramuscular injections?

Answer 20

they allow a more sustained duration of action - up to months.

Question 21

Why are subcutaneous injections good?

Answer 21

they bypass the need for venous access.

Question 22

what is a transdermal drug delivery system?

Answer 22

adhesive patches containing drug are stuck to the skin.

Question 23

what is percutaneous administration? local or systematic

Answer 23

creams ointments and skin patches

local and systematic

Question 24

What do skin patches allow?

Answer 24

Controlled, sustained blood levels of drug.

Question 25

Where does inhalation direct the drug?

Answer 25

Directly to the lungs.

Question 26

Does inhalation have systematic or local effects?

Answer 26

systematic (anaesthetic) and local (salbutamol for asthma)

Question 27

what is essential for inhalation administration?

Answer 27

patient education

Question 28

what are the benefits of inhalation?

Answer 28

they are rapid, direct, not many side effects

Question 29

How can monoclonal antibodies be used to help treat disease?

Answer 29

A toxic drug can get attached to them - and they will travel straight to the cancer site.

Question 30

What is good about liposomal drug delivery.

Answer 30

Since the drugs are packed into liposomes it reduces their toxicity, more drug makes it to the diseased site and less effects other sensitive tissue.

Question 31

What are some nano carriers?

Answer 31

nano shells, nanoparticles, nano tubules.

Question 32

whats good about nano carriers?

Answer 32

they take drugs to a specific location, and have less toxicity and side effects.

Question 33

What happens in a genetic transfer system?

Answer 33

A natural virus with a therapeutic gene injected goes to target cells.