Levolin (levosalbutamol) is generally used to relieve wheezing and is not a standard treatment for a simple dry cough. Flucold AF (chlorpheniramine and phenylephrine) is meant for cold symptoms like congestion. Since your child is only 15 months old and weighs 11 kg, it is safest to consult your pediatrician before giving these medicines. A doctor needs to examine his chest to find the exact cause of the cough and recommend the correct, safe dosage. In the meantime, keeping him well-hydrated can help soothe his throat. Rest assured, with a proper evaluation, he will feel better soon.