Dry Cough

This dry cough's bothering me since Wednesday last week. I thought I was getting better two days after its onset so I went out on weekends to drink beer with friends. Sunday came and the cough got worse. So I called my doctor friend (a cardiologist at St. Luke's) and asked him what's good for my cough. He said Sinecod Forte, 120 mL, one tablespoon four times a day. I immediately bought the cough syrup and have been taking it religiously as prescribed. But until now, I'm still suffering from the same nasty dry cough. I never thought a cough could be this menacing. No phlegm. Just dry, painful, itchy cough. I don't want this to linger for another week. Do you know of any effective over-the-counter cough medication?