Baby Having Catarrh. Having Dry, Chesty Cough. Piriton Syrup Effective?

Please what is the safety as well as efficacy of piriton syrup in treating a very dry chesty cough of a ten month old baby also having catarrh . Infact the whole famiLy are presently having that type of cough. A doctor wanted to nebulise the baby because baby s chest is conjested but I refused to because I feeL that should be a last resort in decongesting the chest and not the first option.also the baby has been nebulised before when suffering from a cough and cold and I just wanted the baby s chest decongested. I hear one or two more nebulisations can make the baby s lungs dependent on drugs to be decongested. I recently started using Silberbird eucalyptus oil .B.Pas aninhaler to reduce d coughs.