Antihistamines

Question 1

When are antihistamines used?

Answer 1

Allergies
hayfever
different formulations for eyes, nose, skin
reduces sneezing and runny nose

Question 2

Which antihistamines are more sedative than others?

Answer 2

Sedative: promethazine
less sedative: chloramphenamine
‘non-sedative’ - cetirizine, loratadine
- caution when drinking, avoid excess alcohol and driving

Question 3

what are contraindications in antihistamines?

Answer 3

Epileptics
liver disease pts
extremes of ages (elderly and children)

Question 4

what is allergen immunotherapy?

Who should it be avoided in?

Answer 4

the immunotherapy uses a allergen containing grass pollen, tree pollen, dust mite - the aim is to reduce asthma symptoms and rhino-conjunctivitis

they also use wasp/bee vemon to reduce risk of severe anaphylaxis

avoid in pregnancy, children under 5, avoid in pts on beta blockers or ACE inhibitors