12 - Principles of Prescribing

Question 1

scenario 1 - 10 y/o complaining of itching epiphora of 2 week durationcol

Answer 1

define clinical problem

Question 2

anti histamine / mast cell stabiliser recommended

Answer 2

signs or symptoms of allergic conjunctivitis

Question 3

topical antihistamine

Answer 3

provides more rapid relief of symptoms

Question 4

mast cell stabiliser

Answer 4

considered first line for prophylaxis

Question 5

consider oral antihistamines or intranasal corticosteroids

Answer 5

if associated symptoms of rhinorrhoea, sneezing or nasal irritation

Question 6

cold compress (flannel and cold water)

Answer 6

may be soothing

Question 7

if a rapid response is required?

Answer 7

topical antihistamine is preferred

Question 8

prevention of allergy over long period is required?

Answer 8

topical mast cell stabilisers first treatment of choice

Question 9

mast cell stabiliser…

Answer 9

• give effective relief of allergic conjunctivitis
• well tolerated
• few adverse effects

Question 10

when to consider systemic anti histamine when

Answer 10

nasal symptoms r present

Question 11

evidence shows combination anti histamine/mast cell stabiliser may be more cost effective.

name one

Answer 11

Olopatadine

Question 12

topical anti allergy drugs for >3 year old

Answer 12

• emedastine (AH) : POM
• Ketotifen (dual-acting) POM
  -Olopatadine (dual acting) POM

Question 13

topical anti allergy drug for >4

Answer 13

Lodoxamide (MCS) POM

Question 14

topical anti allergy drugs for >12

Answer 14

Antazoline (AH) P

Question 15

Azelastien ( dual acting) POM

Answer 15

> 4 years SAC
12 years PAC

Question 16

monitor

Answer 16

• relief of symptoms?
• compliance?
• adverse reactions?

Question 17

provide clear instructions

Answer 17

• instructions on use of drops
• if mast cell stabiliser, advise may take 3 weeks for maximal effect

Question 18

scenario 2

GPC in pregnant(20 weeks)CL wearer exacerbated by hay fever

Answer 18

medicines should be used with caution during pregnancy or when breastfeeding since drugs have potential to cause harm by crossing placenta or entering breast milk

Question 19

what are the principles when prescribing in pregnancy

Answer 19

• avoid unnecessary drug use + consider non-drug therapy
• assess benefit/risk ratio for both mum and baby
• avoid all drugs in 1st trimester
• drugs given in 2nd and 3rd trimester may effect growth of foetus or functional development - or a toxic effect on foetal tissue

Question 20

supply of medicines in pregnancy/lactation

Answer 20

• systemic meds greatest risk
• topical meds vary in their potential risk

Question 21

prescribing in the elderly

Answer 21

reduction in renal drug clearance with age

Question 22

problem for drugs excreted unchanged by kidney + narrow therapeutic index

Answer 22

e.g digoxin or lithium

Question 23

what can worsen renal function

Answer 23

disease states such as diabetes or heart failure