risk factors for common cold
. child care: contact play
. crowded spaces
. chronic stress > 1 month
. underlying chronic disease
- diabetes, CVS
. smoking
clinical presentation for common cold
. incubation period 1-3 days
1) sore scratchy throat
2) sneezing
3) nasal discharge
- colourless -> yellow (azurophil granules in WBC)
4) mild malaise
5) mild-moderate fever < 38.9
6) mild muscle ache and pain
7) day 3-4: non-productive cough -> productive cough -> fade
8) disrupt sleep
complications of cold
1) acute rhinosinusitis
- inflammation of sinus & nasal cavity
- congestion -> infection
2) acute bacterial rhinosinusitis
- bacterial infection after acute rhinosinusitis
- facial pain, purulent discharge
- feel like getting better but sike
3) acute otitis media
- congestion -> affect eustachian tube
4) LRTI
5) exacerbation of asthma, COPD
when to refer for cold
1) fever > 37.5, fever > 3 days
2) underlying cardiopulmonary chronic disease (COPD, CHF, asthma)
3) chest pain
4) SOB
5) AIDS, immunosuppressant patients, elderly, child < 2 yo
6) worsen/new symptoms during self treatment
7) hypersensitivity to prescribed medication
non pharmacotherapy for cold
1) reduce bothersome symptoms
- increase hydration, adequate rest, nutritious diet
- humidification
2) prevent transmission
MOA of congestants
- stimulate alpha adrenergic receptors on nasal blood vessels as agonist
- constriction of nasal blood vessels
- decreased sinus engorgement & mucous oedema
systemic decongestants
- sympathomimetic amines
- pseudoepinephrine, phenylepinephrine
- SE
1) CVS: increase BP, tachycardia, palpitation
2) CNS: fight/flight response -> insomnia, anxiety, restlessness, tremor, headache, excitability
3) others: constipation, anorexia, blurred vision, urinary retention - precaution
1) patients with CVS disease
2) patients with diabetes: activate sympathetic system -> increase glucose production
3) patients with glaucoma/increase ocular pressure
4) patients with hyperthyroidism
5) patients with benign prostate hyperplasia - CI: concurrent/within 2 wks use of MAOi
- potential for abuse: can make amphetamine when bought in large amount
- form of doping for athletes
topical decongestants
- direct, fast acting imidazolines
- advantages: lesser systemic effects
- disadvantages: hard to use, rebound congestion
- oxymetazoline, naphazoline
- SE
1) vehicle & propellant related: stinging, burning, sneezing, local dryness
2) trauma from tip
3) rebound congestion
. vasoconstriction of nasal blood vessel after prolonged use
. increase blood flow -> inflammation
. congestion with subsequent prolong usage
. discontinue, use topical nasal saline/intranasal steroid/systemic decongestants
. don’t use for more than 3-5 days
alternatives to decongestants
1) nasal saline
- MOA: remove mucous & inflammatory mediators & allergens, hydrate mucous membrane, make it more comfortable
2) menthol & camphor containing products
- vix vasorub
- not for young children
3) nasal bulb
- for kids who can’t blow nose
MOA of H1 antihistamines
- block H1 receptor
- 1st gen: anticholinergic
- 2nd gen: inhibit release of mast cell mediators, decrease cell recruitment
side effect of antihistamines
1) CNS
- sedation (1st gen)
- dizziness, confusion, lack of confusion
- paradoxical: tremor, restlessness, insomnia
2) anticholinergic (1st gen)
- dry mouth, urinary retention, palpitation
3) GIT
- N/V, loss of appetite, C, D
4) orthostatic hypotension
5) CVS (Rare)
- QT prolongation (DDI), cardiac arrhythmia (selected 1st gen)
precaution for antihistamines
1) elderly
2) benign prostate hyperplasia
3) glaucoma
4) DDI
- CNS depressants
- drug-food interaction: grapefruit juice & fexofenadine
special population considerations for antihistamines
1) children
- promethazine: caution > 2 yo
- combinations: 6mth - 2 yo: when benefit > risk, > 2 yo: caution
2) pregnant
- antihistamines: chlorpheniramine, dexchlorpheniramine, cetirizine & loratadine safe after 1st trimester
- nasal saline safest decongestant
- lowest dose lowest duration
3) lactating
- chlorpheniramine, dexchlorpheniramine
- no topical/oral decongestant cuz limit breast milk secretion
- nasal saline safest for decongestant
supplements for cold
1) vitamin C
2) Zn
