Chocolate cough syrup?

If you've been following, my 3 1/2 year old son, who was diagnosed with asthma after being hospitalized a couple of times for terrible wheezing.  He now regularly sees a pulmonologist who has him on a whole coterie of meds–Flovent, Zyrtec, Albuterol on an as-needed basis and, since the last visit, Singulair as well. 

In spite of all the meds, every time he comes down with a cold (have you ever seen a kid in nursery school go for more than a week or two without a runny nose?!), he ends up with a terrible, persistent, cough that last for weeks at a time.  Thankfully, so far this season we've avoided wheezing or any hospitalization…but I would love to be able to offer him something besides (or in addition to) Albuterol to quiet his cough…I have definite moments during which I am jealous of parents who had their kids before all cold and cough medicines were taken off the table!