1 and a 1/2 year old cough

My daughter is miserable! (A cold) The main problem is a pesky cough that wont give her a break. I know that coughing is good and that it gets all the gunk out of her chest but i just want to give her a little break to get some sleep. She was just coughing so much that it made her vomit. And the cough is bad enough to wake her up at night. I tried giving her Zarbee's cough syrup but she hates it and was gaging the whole time and wouldnt even take the whole dose. I plan on calling the doctor in the morning but i was just wondering if you ladies knew of something we could get over the counter just for tonight? She is 18 months old. Thanks!