SOME THMs ON URTI
(This may come as a surprise) Selective antihistamines like cetrizine & fexofenadine should not be prescribed in viral rhinitis/cough. They are USELESS.
Histamine is a mediator of inflammation in allergic rhinitis and not in viral infections. Hence, the lack of role of newer anti-histaminics in the latter.
Older anti-histaminics (eg. Chlorpheniramine maleate-CPM) relieve symptoms even of viral infection due to their anti-cholinergic action of drying secretions.
A good dictum to follow before embarking on symptomatic therapy is- ‘whenever possible, treat the underlying cause of dry cough, not the cough itself.’
Do remember that dry cough especially if prolonged, may be due to cough-variant asthma, GERD, tropical eosinophilias, ACE-inhibitors & eosinophilic bronchitis.
Mucolytics: Bromhexine & Ambroxol are most commonly used mucolytics in OPD. Ambroxol is a metabolite of bromhexine utility greater in LRTI thatn URTI.
Mucolytics alter the structure of mucus, reduce the viscosity and facilitate its removal. Mucolytics may disrupt the gastric mucosal barrier hence caution in APD.
Bromhexine & ambroxol are similar in cost & efficacy. Ambroxol dose is 30-60 mg b.d. (e.g. Syp. Ambrolite 5-10 ml b.d.). Bromhexine dose is 8-16 mg (5-10 ml) t.d.s.
In my opinion, percentage of viral URTI getting secondary bacterial infection is <10%. We tend to overestimate this because only patients with secondary infections come back.
A ‘just in case’ prescription in viral URTI means writing an antibiotic to be used if, say, there’s a yellow discharge. Prevents a 2nd visit/phone calls!