It depends if it’s a moist cough or a dry cough. If it’s a moist cough (and you’ll know, because you’ll feel like there’s “gunk” in your lungs that you need to cough up), you need an expectorant cough syrup. One of the cheapest and most effective is “Senega and Ammonia”, and you can get this at most chemists. The “chemist-own” brand is fine, and works the same as more expensive brands. It doesn’t taste particularly nice, but it does work. It helps you to “cough up” mucous & then you don’t have that awful-sounding moist cough anymore.
If it’s a dry cough, you need a cough suppressant, and again, some of the cheaper brands like Durotuss work just as well as the expensive stuff. Anything with Pholcodeine will suppress the dry cough.
Published 7th April 2020