12 - Principles of Prescribing Flashcards
scenario 1 - 10 y/o complaining of itching epiphora of 2 week durationcol
define clinical problem
anti histamine / mast cell stabiliser recommended
signs or symptoms of allergic conjunctivitis
topical antihistamine
provides more rapid relief of symptoms
mast cell stabiliser
considered first line for prophylaxis
consider oral antihistamines or intranasal corticosteroids
if associated symptoms of rhinorrhoea, sneezing or nasal irritation
cold compress (flannel and cold water)
may be soothing
if a rapid response is required?
topical antihistamine is preferred
prevention of allergy over long period is required?
topical mast cell stabilisers first treatment of choice
mast cell stabiliser…
- give effective relief of allergic conjunctivitis
- well tolerated
- few adverse effects
when to consider systemic anti histamine when
nasal symptoms r present
evidence shows combination anti histamine/mast cell stabiliser may be more cost effective.
name one
Olopatadine
topical anti allergy drugs for >3 year old
- emedastine (AH) : POM
- Ketotifen (dual-acting) POM
-Olopatadine (dual acting) POM
topical anti allergy drug for >4
Lodoxamide (MCS) POM
topical anti allergy drugs for >12
Antazoline (AH) P
Azelastien ( dual acting) POM
> 4 years SAC
12 years PAC
monitor
- relief of symptoms?
- compliance?
- adverse reactions?
provide clear instructions
- instructions on use of drops
- if mast cell stabiliser, advise may take 3 weeks for maximal effect
scenario 2
GPC in pregnant(20 weeks)CL wearer exacerbated by hay fever
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
what are the principles when prescribing in pregnancy
- 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
supply of medicines in pregnancy/lactation
- systemic meds greatest risk
- topical meds vary in their potential risk
prescribing in the elderly
reduction in renal drug clearance with age
problem for drugs excreted unchanged by kidney + narrow therapeutic index
e.g digoxin or lithium
what can worsen renal function
disease states such as diabetes or heart failure
