Respiratory Flashcards
Who cannot have anti allergic vaccines?
Asthmatic pts (or use with caution) Preg Child under 5 Bbs users ACEi users
Mode of action of antihistamines?
Binds to H1 receptor site to block the action of histamine
Drugs of sedating antihistamines?
Promethazine BD/TDS Chlorphenamine QDS Alimemazine Hydroxyzine Ketotifen (antihistamine NSAID) clemastine Cyproheptadine
Which antihistamine is the most sedating?
Alimemazine
Which antihistamine causes QT prolongation?
Hydroxyzine
Drugs of non sedating antihistamines?
Acrivastine TDS
Cetirizine and levocetirizine OD
Loratasine and desloratadine OD
Fexofenadine OD
main use of antihistamines?
Allergic rhinitis = hayfever
Reduce rhinorrhoea and sneezing but are usually less effective for nasal congestion
Skin = urticaria/hives
Which antihistamines are used in N&V?
Cinnarizine
Cyclizine
Promethazine
Buclizine (with migraines only OTC)
Which antihistamines are used for insomnia?
Promethazine
Diphenhydramine
Both OTC
Which antihistamines are used adjunct in emergency anaphylaxis and angiodema?
Chlorphenamine /promethazine injection
Side effect of sedating antihistamines?
More sedating and more antimuscarnics
Advantage of non sedating antihistamines?
Less sedating and less psychomotor impairment
Important pt advise on antihistamines?
Avoid alcohol
Driving may be impaired
Important cautions when using antihistamines?
Benign prostatic hyperplasia cas urinary retention
Glaucoma because raised inrtraocular pressure
Severe liver impairment (sedation precipitates hepatic coma)
What’s the unique odd antihistamine?
Hydroxyzine
MHRA warning on Hydroxyzine?
QT prolongation
Torsade de pointes
Use short term only
Max adult dose of Hydroxyzine?
100mg
Contraindications in Hydroxyzine?
Anything that increases risk of QT prolongation
What’s the name of monoclonal antibody that binds to IgE and thus used in allergic conditions?
Omalizumab injection
Used for severe persistent allergic asthma for 6plus if inadequate response to high dose inhaled corticosteroid and who need frequent oral corticosteroid for more that 4 courses in the last year
Chronic spontaneous urticaria in 12 plus
If inadequate response to H1 antihistamines, leukotriene receptor antagonists
Side effects of omalizumab?
Churg strauss syndrome
Hyoersensititvy reactions
First management of anaphylaxis in community?
Secure airways Restore BP Raise lefs Lay flat If sick or unconscious, place in recovery position
How to administer adrenaline?
Inject to anterolateral aspect of mid thigh
Strength of adrenaline?
1 in 1000 solution
Dose of adrenaline in child 1 month to 5yrs?
150mcg repeated every 5 mins
