Drug delivery systems

Question 1

pessaries

Answer 1

inserted into the vagina to treat infection or as a contraceptive.

Question 2

suppositories

Answer 2

inserted into the rectum or vagina to dissolve.
useful in young and old- also those that can’t swallow
used for constipation etc

Question 3

main types of delivery systems

Answer 3

oral, IV, transdermal, carrier based

Question 4

what is important in working out which way to deliver a drug to the patient?

Answer 4

it should be tailored to the patients needs, pharmacological characteristics and disease state
i.e suppository over IV or injection if epileptic child etc

Question 5

what are the 3 key factores that determine the drug delivery system we use?

Answer 5

• the dose of the drug to be given
• the frequency of administration
• the timing of administration

Question 6

what do you have to take into consideration when choosing a dosage regime?

Answer 6

first find out the recommended dose
then does the patient have:-
impaired renal or hepatic function?
consider age and weight
consider the disease being treated and drug toxicity
give a starting dose then increase it to achieve the desired effect

Question 7

naso-gastric or PEG tubes?

Answer 7

tube through the nose to the stomach
PEG= feeding tube is placed through the abdominal wall and into the stomach
DRUGS GIVEN IN THIS WAY ARE ABSORBED EXTREMELY RAPIDLY

Question 8

why are suspensions good for some drugs?

Answer 8

some drugs are unpalatable (foul taste) so this makes them better tolerated

Question 9

prolong or delayed release formulations?

Answer 9

putting the whole dose in the drug that can then release sequentially at different times in the body- prevents problem of people forgetting to take medication

Question 10

advantages of tablet or capsule use

Answer 10

easy to make
accuracy of dose
drug stability

Question 11

enteric coated tablets?

Answer 11

enteric coating delays disintegration of the tablet until it reaches the small intestine- this protects the drug from stomach acid
or protect the stomach from the drug ie aspirin

Question 12

surgical implants

Answer 12

progesterone contraception

testosterone

Question 13

IV importance of timing of drug delivery?

Answer 13

Important to give IV at correct time

May need to let drug diffuse for say an hour so have to do that otherwise could be severe implications

Question 14

bolus?

Answer 14

administration of a small amount of medication, drug, or other compound usually in a short time (generally within 1 - 30 minutes) in order to raise its concentration in blood to an effective level.

Question 15

IV formulations may be given

Answer 15

rapidly
slowly to prevent toxicity
continuous infusion- accurate control of blood levels esp when a drug has a narrow therapeutic index ie optimal time when it’s active and not inactive or toxic

Question 16

transdermal drug delivery

Answer 16

drug crossed the skin surface by diffusion by percutaneous absorption and goes into the systemic circulation
bypasses first pass hepatic inactivation