What is the sign that dry cough is getting better and can stop taking medicine? Is it ony if I totally not coughing? Cos med cause drowsiness in day

Stop anytime.. It's just a cough suppressant correct? It's not an antibiotic or asthma medicine? If the medicine is bothering you with drowsiness more than it is helping your cough, you can stop it.
OK to stop. Cough medicines are only for symptoms so if your cough is better, you can stop the cough medication. If you were given an antibiotic on the other hand, you always want to finish the course.