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

Dextromethorphan is used to treat a cough. It is available over-the-counter alone and is also present in many over-the-counter and prescription combination medications.

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

Do not give dextromethorphan 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 use dextromethorphan if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), tranylcypromine (Parnate), or methylene blue injection within the past 14 days. Serious, life-threatening side effects can occur if you take dextromethorphan before the MAO inhibitor has cleared from your body.

Do not use any other over-the-counter cough, cold, or allergy medication without first asking your doctor or pharmacist. If you take certain products together you may accidentally take too much of one or more types of medicine. Read the label of any other medicine you are using to see if it contains dextromethorphan. Dextromethorphan will not treat a cough that is caused by smoking, asthma, or emphysema.

Before taking this medicine

Do not use dextromethorphan if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), tranylcypromine (Parnate), or methylene blue injection within the past 14 days. Serious, life-threatening side effects can occur if you take dextromethorphan before the MAO inhibitor has cleared from your body.

Ask a doctor or pharmacist about using dextromethorphan if you have emphysema or chronic bronchitis.

It is unknown whether dextromethorphan is harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Dextromethorphan may pass into breast milk. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Artificially-sweetened liquid forms of cough medicine may contain phenylalanine. This would be important to know if you have phenylketonuria (PKU). Check the ingredients and warnings on the medication label if you are concerned about phenylalanine.

Dextromethorphan comes as a liquid-filled capsule, a chewable tablet, a dissolving strip, a solution (liquid), an extended-release (long-acting) suspension (liquid), and a lozenge to take by mouth. It is usually taken every 4 to 12 hours as needed. Follow the directions on the package or prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand.

Dextromethorphan should only be used according to the label or package directions. Do not take more than the recommended amount of dextromethorphan in a 24-hour period. Refer to the package or prescription label to determine the amount contained in each dose. Taking dextromethorphan in large amounts can cause serious side effects or death.

Dextromethorphan comes alone and in combination with antihistamines, cough suppressants, and decongestants. Ask your doctor or pharmacist for advice on which product is best for your symptoms. Check nonprescription cough and cold product labels carefully before using 2 or more products at the same time. These products may contain the same active ingredient(s) and taking them together could cause you to receive an overdose. This is especially important if you will be giving cough and cold medications to a child.

Nonprescription cough and cold combination products, including products that contain dextromethorphan, can cause serious side effects or death in young children. Do not give these products to children younger than 4 years of age. If you give these products to children 4-11 years of age, use caution and follow the package directions carefully.

If you are giving dextromethorphan or a combination product that contains dextromethorphan to a child, read the package label carefully to be sure that it is the right product for a child of that age. Do not give dextromethorphan products that are made for adults to children.

Before you give a dextromethorphan product to a child, check the package label to find out how much medication the child should receive. Give the dose that matches the child's age on the chart. Ask the child's doctor if you don't know how much medication to give the child.

If you are taking the liquid, do not use a household spoon to measure your dose. Use the measuring spoon or cup that came with the medication or use a spoon made especially for measuring medication.

If you are using the dissolving strips, place them on your tongue and swallow after they melt.

If you are taking the chewable tablets you can allow them to melt in your mouth or you can chew them before swallowing.

If you are taking the extended-release suspension, shake the bottle well before each use to mix the medication evenly.

If you are taking the lozenges, allow them to slowly melt in your mouth.

Stop taking dextromethorphan and call your doctor if your cough does not get better within 7 days, if your cough goes away and comes back, or if your cough occurs with a fever, rash, or headache.

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

Do not give dextromethorphan to a child younger than 4 years old.

Always ask a doctor before giving cough or cold medicine to a child. Death can occur from the misuse of cough or cold medicine in very young children.

Measure the liquid form of dextromethorphan with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Allow the dextromethorphan lozenge or disintegrating strip to dissolve in your mouth.

Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication. Talk with 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 to have any type of surgery, tell the surgeon ahead of time if you have taken dextromethorphan within the past few days.

Store dextromethorphan at room temperature, away from heat, light, and moisture.

Do not use dextromethorphan if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), tranylcypromine (Parnate), or methylene blue injection within the past 14 days. Serious, life-threatening side effects can occur if you take dextromethorphan before the MAO inhibitor has cleared from your body.

Ask a doctor or pharmacist about using dextromethorphan if you have emphysema or chronic bronchitis.

It is unknown whether dextromethorphan is harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Dextromethorphan may pass into breast milk. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Artificially-sweetened liquid forms of cough medicine may contain phenylalanine. This would be important to know if you have phenylketonuria (PKU). Check the ingredients and warnings on the medication label if you are concerned about phenylalanine.

Since cough medicine is usually taken only as 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. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include nausea, vomiting, drowsiness, dizziness, difficulty breathing, fast heartbeat, or seizures (convulsions). Overdose can also result in coma or death.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unless your doctor tells you otherwise, continue your normal diet.

Avoid drinking alcohol. It can increase some of the side effects of dextromethorphan. This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without your doctor's advice. Taking a stimulant together with cough medicine can increase your risk of unpleasant side effects.

Do not use any other over-the-counter cough, cold, or allergy medication without first asking your doctor or pharmacist. Dextromethorphan is contained in many combination medicines available over the counter. If you take certain products together you may accidentally take too much of this medicine. Read the label of any other medicine you are using to see if it contains dextromethorphan.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Stop using dextromethorphan and call your doctor at once if you have any of these serious side effects:

• severe dizziness, anxiety, restless feeling, or nervousness;

• seizures or convulsions;

• confusion, hallucinations; or

• slow, shallow breathing.

Less serious side effects are more likely, such as stomach upset.

This is not a complete list of dextromethorphan 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.

Before taking dextromethorphan, tell your doctor if you are using any of the following drugs:

• celecoxib (Celebrex);

• cinacalcet (Sensipar);

• darifenacin (Enablex);

• imatinib (Gleevec);

• quinidine (Quinaglute, Quinidex);

• ranolazine (Ranexa)

• ritonavir (Norvir);

• sibutramine (Meridia);

• terbinafine (Lamisil);

• medicines to treat high blood pressure; or

• antidepressant medications such as amitriptyline (Elavil, Etrafon), bupropion (Wellbutrin, Zyban), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), imipramine (Janimine, Tofranil), paroxetine (Paxil), sertraline (Zoloft), and others.

This list is not complete and there are numerous other drugs that can interact with dextromethorphan. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Ask your pharmacist any questions you have about dextromethorphan.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Alka-Seltzer Plus Cold and Cough Formula® (containing Aspirin, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Alka-Seltzer Plus Day and Night Cold Formulas® (containing Aspirin, Dextromethorphan, Phenylephrine)
• Alka-Seltzer Plus Day Non-Drowsy Cold Formula® (containing Acetaminophen, Dextromethorphan, Phenylephrine)
• Alka-Seltzer Plus Flu Formula® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Alka-Seltzer Plus Mucus and Congestion® (containing Dextromethorphan, Guaifenesin)
• Alka-Seltzer Plus Night Cold Formula® (containing Aspirin, Dextromethorphan, Doxylamine, Phenylephrine)
• Children's Dimetapp Cold and Cough® (containing Brompheniramine, Dextromethorphan, Phenylephrine)
• Children's Dimetapp Multisymptom Cold and Flu® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Children's Mucinex Cough® (containing Dextromethorphan, Guaifenesin)
• Children's Mucinex Multi-Symptom Cold® (containing Dextromethorphan, Guaifenesin, Phenylephrine)
• Children's Robitussin Cough and Cold CF® (containing Dextromethorphan, Guaifenesin, Phenylephrine)
• Children's Robitussin Cough and Cold CF® (containing Dextromethorphan, Guaifenesin, Phenylephrine)
• Children's Robitussin Cough and Cold Long-Acting® (containing Chlorpheniramine, Dextromethorphan)
• Children's Sudafed PE Cold and Cough® (containing Dextromethorphan, Phenylephrine)
• Coricidin HBP Chest Congestion and Cough® (containing Dextromethorphan, Guaifenesin)
• Coricidin HBP Cough and Cold® (containing Chlorpheniramine, Dextromethorphan)
• Coricidin HBP Day and Night Multi-Symptom Cold® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Guaifenesin)
• Coricidin HBP Maximum Strength Flu® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan)
• Coricidin HBP Nighttime Multi-Symptom Cold® (containing Acetaminophen, Dextromethorphan, Doxylamine)
• Diabetic Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Dimetane DX® (containing Brompheniramine, Dextromethorphan, Pseudoephedrine)
• Mucinex Cough for Kids® (containing Dextromethorphan, Guaifenesin)
• Mucinex DM® (containing Dextromethorphan, Guaifenesin)
• PediaCare Children's Cough and Congestion® (containing Dextromethorphan, Guaifenesin)
• PediaCare Children's Fever Reducer Plus Cough and Runny Nose® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan)
• PediaCare Children's Fever Reducer Plus Cough and Sore Throat® (containing Acetaminophen, Dextromethorphan)
• PediaCare Children's Fever Reducer Plus Flu® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• PediaCare Children's Fever Reducer Plus Multi-Symptom Cold® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Robitussin Cough and Chest DM® (containing Dextromethorphan, Guaifenesin)
• Robitussin Cough and Cold CF® (containing Dextromethorphan, Guaifenesin, Phenylephrine)
• Robitussin Cough and Cold Long-Acting® (containing Chlorpheniramine, Dextromethorphan)
• Robitussin Night Time Cough, Cold, and Flu® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Sudafed PE Cold/Cough® (containing Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine)
• Sudafed PE Day/Night Cold® (containing Acetaminophen, Dextromethorphan, Diphenhydramine, Guaifenesin, Phenylephrine)
• Theraflu Cold and Cough® (containing Dextromethorphan, Pheniramine, Phenylephrine)
• Theraflu Daytime Severe Cold and Cough® (containing Acetaminophen, Dextromethorphan, Phenylephrine)
• Theraflu Max-D Severe Cold and Flu® (containing Acetaminophen, Dextromethorphan, Guaifenesin, Pseudoephedrine)
• Triaminic Cough and Sore Throat® (containing Acetaminophen, Dextromethorphan)
• Triaminic Day Time Cold and Cough® (containing Dextromethorphan, Phenylephrine)
• Triaminic Multi-Symptom Fever® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan)
• Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Tylenol Cold and Cough Daytime® (containing Acetaminophen, Dextromethorphan)
• Tylenol Cold and Cough Nighttime® (containing Acetaminophen, Dextromethorphan, Doxylamine)
• Tylenol Cold and Flu Severe® (containing Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine)
• Tylenol Cold Multi-Symptom Nighttime® (containing Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylephrine)
• Tylenol Cold and Mucus Severe® (containing Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine)
• Vicks Children's NyQuil Cold and Cough® (containing Chlorpheniramine, Dextromethorphan)
• Vicks DayQuil Cold and Flu Relief® (containing Acetaminophen, Dextromethorphan, Phenylephrine)
• Vicks DayQuil Cold and Flu Symptom Relief Plus Vitamin C® (containing Acetaminophen, Dextromethorphan, Phenylephrine)
• Vicks DayQuil Mucus Control DM® (containing Dextromethorphan, Guaifenesin)