Codeine is a narcotic cough suppressant. It affects the signals in the brain that trigger cough reflex.

Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.

Guaiatussin AC is a combination medicine used to treat cough and chest congestion caused by allergies, the common cold, or the flu.

Guaiatussin AC will not treat a cough that is caused by smoking, asthma, or emphysema.

Guaiatussin AC may also be used for purposes not listed in this medication guide.

Codeine can slow or stop your breathing, and may be habit-forming. MISUSE OF Guaiatussin AC CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription.

Do not give this medicine to anyone under 18.

Follow all directions on your prescription label. Codeine can slow or stop your breathing. Never use Guaiatussin AC in larger amounts, or for longer than prescribed. Cough or cold medicine is usually taken only for a short time until your symptoms clear up.

Codeine may be habit-forming, even at regular doses. Never share Guaiatussin AC with another person, especially someone with a history of drug abuse or addiction. MISUSE OF NARCOTIC MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. Selling or giving away codeine is against the law.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Call your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache or skin rash.

Store at room temperature away from moisture and heat. Do not freeze. Keep track of the amount of medicine used from each new bottle. Codeine is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.

You should not take this medicine if you are allergic to codeine or guaifenesin.

In some people, codeine breaks down rapidly in the liver and reaches higher than normal levels in the body. This can cause dangerously slow breathing and may cause death, especially in a child.

Do not give this medicine to anyone under 18.

To make sure Guaiatussin AC is safe for you, tell your doctor if you have ever had:

• a cough with mucus;

• asthma, COPD, or other breathing disorder;

• blockage in your digestive tract (stomach or intestines);

• a head injury or brain tumor;

• low blood pressure; or

• drug or alcohol addiction.

If you use codeine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on habit-forming medicine may need medical treatment for several weeks. Tell your doctor if you are pregnant or plan to become pregnant.

Do not breast-feed. Codeine can pass into breast milk and may cause drowsiness, breathing problems, or death in a nursing baby. Do not breast-feed.

Since Guaiatussin AC is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. A codeine overdose can be fatal, especially in a child or other person using the medicine without a prescription. Overdose symptoms may include slow breathing and heart rate, severe drowsiness, muscle weakness, cold and clammy skin, pinpoint pupils, and fainting.

Guaiatussin AC may impair your thinking or reactions. Avoid driving or operating machinery until you know how this medicine will affect you. Dizziness or severe drowsiness can cause falls or other accidents.

Do not drink alcohol. Dangerous side effects or death could occur.

Ask a doctor or pharmacist before using any other cough or cold medicine. Many combination medicines contain guaifensin. Taking certain products together can cause you to get too much of this medicine.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Like other narcotic medications, codeine can slow your breathing. Death may occur if breathing becomes too weak.

A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

This medicine may cause serious side effects. Stop using this medicine and call your doctor at once if you have:

• noisy breathing, sighing, shallow breathing;

• a slow heart rate or weak pulse;

• severe dizziness or drowsiness;

• confusion, hallucinations, unusual thoughts or behavior;

• little or no urinating;

• severe constipation; or

• slow heart rate, weak or shallow breathing.

Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.

Common side effects of Guaiatussin AC may include:

• constipation; or

• mild drowsiness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Taking Guaiatussin AC with other drugs that make you sleepy or slow your breathing can cause dangerous side effects or death. Ask your doctor before taking a sleeping pill, narcotic pain medicine, prescription cough medicine, a muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with codeine and guaifenesin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.