Alcohol is the safest solvent for drugs that do not mix well with water, as pharmacists have known since ancient times.
Safe, that is, for the general population.
For an alcoholic or anyone else who does not want to ingest spirits, a pharmacist will recommend a tablet or lozenge, or for a severe cough, a spray with a very small amount of alcohol that mostly evaporates.
There is some pharmacological activity in the alcohol in cough syrup, but normally the concentration is very low.
For example, a teaspoon of something that is 15 to 20 percent alcohol has only about 1 milliliter of pure alcohol, as against about 15 milliliters in a shot of bourbon.