One of the oldest and most effective cough medicines is laudanum, a tincture prepared from the opium poppy, reports Fox News. It contains morphine and codeine, which are antitussive drugs that suppress the cough reflex. It is still available by prescription.
Hard liquor, specifically whiskey, is also widely known as an age-old cough remedy. An example recipe is available at Food Republic. Gargling with salt water is another proven way to soothe a cough and accompanying sore throat, according to Mayo Clinic. Finally, honey is the top natural fix for a bad cough, as reported by Healthline. One study found honey to be superior to dextromethorphan, the active ingredient in Robitussin.