Dexchlorpheniramine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

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

Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

Deltuss DMX is a combination medicine used to treat runny or stuffy nose, sneezing, itching, watery eyes, cough, and sinus congestion caused by allergies, the common cold, or the flu.

Deltuss DMX will not treat a cough that is caused by smoking, asthma, or emphysema.

Deltuss DMX may also be used for purposes not listed in this medication guide.

Do not use cough or cold medicine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include furazolidone, isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended. Cough or cold medicine is usually taken only for a short time until your symptoms clear up.

Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Measure liquid medicine 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, 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 and heat. Do not freeze.

You should not use this medicine if you are allergic to dexchlorpheniramine, dextromethorphan, or pseudoephedrine.

Do not use cough or cold medicine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include furazolidone, isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have other medical conditions, especially:

• asthma or COPD, cough with mucus, or cough caused by smoking, emphysema, or chronic bronchitis;

• a blockage in your stomach or intestines;

• glaucoma;

• kidney disease;

• liver disease;

• diabetes;

• heart disease or high blood pressure;

• a thyroid disorder;

• cough with mucus, or cough caused by emphysema or chronic bronchitis;

• enlarged prostate or urination problems; or

• if you take potassium (Cytra, Epiklor, K-Lyte, K-Phos, Kaon, Klor-Con, Polycitra, Urocit-K).

FDA pregnancy category C. It is not known whether this medication will harm an unborn baby. Do not use cough or cold medicine without medical advice if you are pregnant.

This medicine may pass into breast milk and may harm a nursing baby. Antihistamines and decongestants may also slow breast milk production. Do not use cough or cold medicine without medical advice if you are breast-feeding a baby.

Since cough or cold medicine is taken when needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Ask a doctor or pharmacist before using any other cold, allergy, cough, or sleep medicine. Deltuss DMX are contained in many combination medicines. Taking certain products together can cause you to get too much of a certain drug. Check the label to see if a medicine contains an antihistamine, cough suppressant (antitussive), or decongestant.

Drinking alcohol can increase certain side effects of this medication.

This medicine may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

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

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

• fast, slow, or uneven heart rate;

• severe headache, mood changes, hallucinations;

• severe dizziness or anxiety, feeling like you might pass out;

• tremor, seizure (convulsions);

• easy bruising or bleeding, unusual weakness;

• fever;

• little or no urinating;

• shortness of breath; or

• dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, uneven heartbeats, seizure).

Common side effects of Deltuss DMX may include:

• mild headache;

• mild dizziness, drowsiness;

• dry mouth, nose, or throat;

• nausea, diarrhea, constipation, upset stomach;

• feeling nervous, restless, or irritable;

• blurred vision; or

• sleep problems (insomnia).

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.

Ask a doctor or pharmacist before using Deltuss DMX if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together. Not all possible interactions are listed in this medication guide.

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking Deltuss DMX with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.