Entex HC is a combination medicine used to treat cough, stuffy nose, sinus congestion, and chest congestion caused by the common cold.

Entex HC will not treat a cough with mucus, or cough that is caused by smoking, emphysema, or chronic bronchitis.

Entex HC contains a narcotic cough medicine and may be habit-forming.

Entex HC may also be used for other purposes not listed in this medication guide.

MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it.

Fatal side effects can occur if you use Entex HC with alcohol, or with other drugs that cause drowsiness or slow your breathing.

Follow the directions on your prescription label and read all medication guides. Never use Entex HC in larger amounts, or for longer than prescribed. Take this medicine only until your symptoms clear up.

Never share opioid medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it. Selling or giving away opioid medicine is against the law.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

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

If you need surgery or medical tests, tell the surgeon or doctor ahead of time if you have taken a cough or cold medicine within the past few days.

Store at room temperature away from moisture, heat, and light. Keep track of your medicine. You should be aware if anyone is using it improperly or without a prescription.

Do not keep leftover medication. Just one dose can cause death in someone using this medicine accidentally or improperly. Read and carefully follow the instructions provided with this medicine about how to safely dispose of any unused portion.

Do not use this medicine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

You should not use this medicine if you are allergic to guaifenesin, hydrocodone, or pseudoephedrine, or if you have:

• narrow-angle glaucoma;

• severe or uncontrolled high blood pressure;

• coronary artery disease (clogged arteries); or

• if you are unable to urinate.

This medicine is not approved for use by anyone younger than 18 years old.

Tell your doctor if you have ever had:

• asthma or other breathing problems;

• a head injury or increased pressure inside your skull;

• diabetes;

• thyroid disorder;

• Addison's disease (an adrenal gland disorder);

• liver or kidney disease;

• an enlarged prostate or urination problems; or

• stomach problems.

If you use hydrocodone 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.

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

Since this medicine is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of hydrocodone can be fatal.

Overdose symptoms may include extreme drowsiness, feeling weak or limp, cold and clammy skin, breathing problems, fast or slow heartbeats, confusion, hallucinations, slurred speech, blue lips, slow breathing, fainting, or breathing that stops.

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

Avoid driving or operating machinery until you know how Entex HC will affect you. Dizziness or severe drowsiness can cause falls or other accidents.

Ask a doctor or pharmacist before using other cough or cold medicines that may contain similar ingredients.

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

This medicine can slow or stop your breathing, and death may occur. 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;

• confusion, severe weakness or drowsiness;

• tremors, severe restlessness;

• a seizure;

• irregular heartbeats;

• severe headache, blurred vision, pounding in your neck or ears;

• a light-headed feeling, like you might pass out;

• severe constipation, stomach pain; or

• adrenal gland problems--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

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

Common side effects of Entex HC may include:

• dizziness, drowsiness;

• headache;

• sleep problems (insomnia);

• nausea; or

• low blood pressure.

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.

Using this medicine with other drugs that slow your breathing can cause dangerous side effects or death. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Opioid medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:

• cold or allergy medicines, bronchodilator asthma/COPD medication, or a diuretic ("water pill");

• medicines for motion sickness, irritable bowel syndrome, or overactive bladder;

• other narcotic medications--opioid pain medicine or prescription cough medicine;

• a sedative like Valium--diazepam, alprazolam, lorazepam, Xanax, Klonopin, Versed, and others; or

• drugs that make you sleepy or slow your breathing--a sleeping pill, muscle relaxer, medicine to treat mood disorders or mental illness.

This list is not complete. Other drugs may affect Entex HC, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.