Can I use Pulnozin and Mucopect Kids interchangeably in a one-year-old child?

Pulnozin and Mucopect Kids are syrups with the same composition in terms of carbocysteine content (50 mg / ml). They differ in the lower limit of the age from which they can be used. The manufacturer of Pulnozin set this limit at 2 years of age, and in the case of Mucopect Kids it is 6 years of age. Based on the documentation of these drugs, I can provide information that both syrups are contraindicated in a one-year-old child. This is due to the possibility of excessive accumulation of syrup-diluted secretions in the respiratory tract and the severity of symptoms. However, the doctor may recommend the use of drugs off-label, guided by the best scientific evidence, this is the so-called off-label use: https://www.gdziepolek.pl/artykuly/leczenie-off-label-poza-wskazaniami