Let's take a minute to talk about your medication. 

This is Cheratussin-AC, and you should take it exactly as directed by your doctor. 

This medicine relieves coughing and loosens mucus so your body can get rid of it. Each 1 teaspoonful is equal to 5 milliliters, and contains both guaifenesin 100 mg and codeine 10 mg. 

It's important to measure each dose with a measuring spoon. This medicine should not be given to children under 2 years of age. 

It's usually well-tolerated, but some side effects can occur, like nausea or mild drowsiness. So, don't drive or do other activities that require you to be alert until you know how it affects you. After several doses, it could also cause constipation, and your pharmacist can advise how to reduce this. If these or other side effects become reasons you want to stop taking this medicine, please talk to your doctor or pharmacist. 

To reduce serious side effects, it is important not to take any more than prescribed, and ask your doctor or pharmacist before taking any new medicines. You should also avoid alcohol and other medicines that cause drowsiness. You should call your doctor if a cough lasts for more than 7 days, comes back, or occurs with fever, rash or a lasting headache. 

This medication has an ingredient that can be abused or misused by others, so store it securely, and away from children. 

For best results, take it only as prescribed, and drink plenty of water to reduce constipation and improve your cough.