Allergic Rhinitis Flashcards
What are the classical S/Sx of allergic rhinitis?
How long will S/Sx be present to consider allergic rhinitis as DDx?
1) Rhinorrhea (runny nose)
2) Nasal congestion (blocked nose)
3) Nasal pruritis (itchy nose)
4) Sneezing
S/Sx MUST be present for at least 2 days in a row, AND last for more than an hour on most days.
- Conjunctivitis may occasionally accompany these classical S/Sx
What are some possible triggers of allergic rhinitis?
Allergens (pollen, moulds, dust mites, pet dander, dust, food)
House dust mites are the most common aeroallergen in SG.
What are some differential diagnoses (DDx) that may help identify whether a patient may have allergic rhinitis?
When should you refer?
- Absence of itchy nose (pruritis)
- Antihistamines not helping to relieve S/Sx
REFER to ENT specialist:
- Unilateral obstruction w/o classical S/Sx
- Mucopurulent rhinorrhea (i.e. NOT clear discharge) -> Bacterial URTI
- Posterior rhinorrhea (post nasal drip)
- Pain around the eye -> sinusitis
- Recurrent epistaxis (i.e. nose bleed)
- Anosmia / loss of smell
What is some non-pharmacological advice to minimise allergic rhinitis from triggering?
1) Avoidance/prevention of known allergens
- Frequent vacuuming of carpet, plastic covers
- Minimise overstuffing chairs & dust-collecting boxes under bed
- Wash curtains, bedsheets and stuffed animals regularly
2) Include HEPA filtration filter in air-conditioners
3) Bathe animals regularly
- Recommend to keep them out of house, if not, outside bedroom
4) Remove sources of mould growth
- Increase ventilation
- Remove stagnant water
- Clean humidifiers, vaporizers
Based on TTSH P-Sales formulary, which medications are available to manage patients with allergic rhinitis?
Oral antihistamines (intermittent & mild persistent S/Sx):
1) Chlorpheniramine 4mg tab (Piriton)
2) Cetirizine 10mg tab (generic & Zyrtec)
3) Loratadine 10mg tab (generic)
4) Fexofenadine 120mg (GSL) or 180mg (POME) tab
Intranasal corticosteroids (moderate to severe persistent S/Sx):
1) Avayms 27.5mcg/actuation nasal spray (fluticasone furoate)
2) Nasocort 55mcg/actuation nasal spray (triamcinolone acetonide)
3) Exemis (?) 50mcg/actuation nasal spray (mometasone furoate)
What are some advantages and disadvantages of using chlorpheniramine for allergic rhinitis?
1) Chlorpheniramine 4mg tab (Piriton)
- 4mg PO q4-6h; max dose = 24 mg/day
- S/E: Drowsiness, dry mouth, urinary retention, abdominal discomfort
(+) sedating, useful to be taken ON to manage nasal irritation
(+) suitable for pregnant patients
(-) more drowsy as 1st gen antihistamines
(-) anticholinergic effects may interfere with BPH management (tamsulosin)
What are some advantages and disadvantages of using cetirizine for allergic rhinitis?
2) Cetirizine 10mg tab (generic & Zyrtec)
- 10mg PO OD; CrCL = 11 - 30 mL/min: 5mg PO OD
- Max internal supply: 50 tabs
- S/E: Potential drowsiness, dry mouth
(+) less sedating than chlorpheniramine, can be taken in the day generally w/o lifestyle disturbance
(+) 2nd gen antihistamine w/o anticholinergic activities, suitable for BPH pt
(+) Cheaper for generic than loratadine ($1.61 vs ~$3.40 per 10 tabs)
(-) more sedating than loratadine; more optimal for pt who needs to concentrate (e.g. drivers)
(-) renal dose adjustment required
What are some advantages and disadvantages of using loratadine for allergic rhinitis?
3) Loratadine 10mg tab (generic)
- 10 mg PO OD; CrCl <30 mL/min: 10 mg q48h
- Max internal supply: 50 tabs
- S/E: headache
(+) least sedating, can be taken in the day w/o lifestyle disturbance
(+) 2nd gen antihistamine w/o anticholinergic activities, suitable for BPH pt
(-) renal dose adjustment required
(+) More expensive than generic cetirizine (~$3.40 vs $1.61 per 10 tabs)
What are some advantages and disadvantages of using fexofenadine for allergic rhinitis?
4) Fexofenadine 120mg (GSL) or 180mg (POME) tab
- One 120mg or 180mg tab OD; CrCl <50 mL/min: 60 mg OD
- Max HSA supply for POME: 10 tabs
- S/E: headache, vomiting
(+) least sedating, can be taken in the day w/o lifestyle disturbance
(+) 2nd gen antihistamine w/o anticholinergic activities, suitable for BPH pt
(-) renal dose adjustment required
What are some advantages and disadvantages of using Avamys for allergic rhinitis?
1) Avamys 27.5mcg/actuation nasal spray (fluticasone furoate)
- POME: 1 spray per nostril; max dose: 2 sprays per nostril/day
- Refer if pt requires more than 2 sprays per nostril/day
- Max HSA supply for POME: 3 months’ supply
- S/E: Headache, nose bleeds (epistaxis)
(+) suitable for non-allergic rhinitis
(-) Increased risk for systemic effects of corticosteroids if misued
What are some advantages and disadvantages of using Nasocort for allergic rhinitis?
2) Nasocort 55mcg/actuation nasal spray (triamcinolone acetonide)
- POME: 1 spray per nostril; max dose: 2 sprays per nostril/day
- Refer if pt requires more than 2 sprays per nostril/day
- Max HSA supply for POME: 3 months’ supply
- S/E: Infections (flu, pharyngitis, rhinitis)
(+) suitable for non-allergic rhinitis
(-) Increased risk for systemic effects of corticosteroids if misued
What are some advantages and disadvantages of using Exemis / Nasonex for allergic rhinitis?
3) Exemis (?) 50mcg/actuation nasal spray (mometasone furoate)
- POME: 1 spray per nostril; max dose: 2 sprays per nostril/day
- Refer if pt requires more than 2 sprays per nostril/day
- Max HSA supply for POME: 3 months’ supply
- S/E: Headache, nausea, vomiting, nose bleeds (epistaxis)
(+) suitable for non-allergic rhinitis
(-) Increased risk for systemic effects of corticosteroids if misued
