Cough in kids less than 6yrs old whether being with sputum i.e. wet or without i.e. dry and parental asking about any medicine stopping this symptom certainly if being dry i.e. irritating and disturbing sleep. So most studies being done on this subject proved the following:
a) It is not wise to suppress cough because it is natural defense mechanism to expel infected mucus i.e. sputum out of the body and clearing the airways to improve oxygenation so never to prescribe antitussive i.e. cough suppressant.
b) sputum mucolytic agents and there are many agents their purpose to liquify it and get it watery to be easy expectorated again studies proved that the best muculytic agent is Good Hydration so no need to use except where there is a mucus retention in the lungs like case of brocheictasis.
c) WHO recommendation made about 6 yrs back was never to prescribe any cough medicine whether antitussive or mucolytic to kids less than 6 yrs old.
Myself and since about 10 years I had not prescribed any cough suppressant to children despite of age but if kids older than 6 years old I do prescribe mucolytic agent made certainly for kids like amydramine syrup which contains antihistamine diphenhydramine and without restrictions. In kids less than 6yrs old again I do prescribe mucolytic made for kids like soolan or Amydramine pediatric syrup in trial to hit 2 birds which are sedating and antihistamine effects and satisfying anxious parents and it does work almost in all cases.