chlorpheniramine, dextromethorphan, and methscopolamine

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Pronunciation: KLOR fen IR a meen, DEX troe me THOR fan, and METH skoe POE la meen

Brand: Extendryl DM

What is the most important information I should know about this medicine?

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

What is chlorpheniramine, dextromethorphan, and methscopolamine?

Chlorpheniramine and methscopolamine are antihistamines that reduce 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.

Chlorpheniramine, dextromethorphan, and methscopolamine is a combination medicine used to treat cough, runny or stuffy nose, sneezing, itching, and watery eyes caused by allergies, the common cold, or the flu.

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

Chlorpheniramine, dextromethorphan, and methscopolamine may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking this medicine?

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

To make sure this medicine is safe for you, tell your doctor if you have:

  • asthma or COPD, cough with mucus, or cough caused by smoking, emphysema, or chronic bronchitis;
  • a blockage in your digestive tract (stomach or intestines);
  • high blood pressure, heart disease;
  • liver or kidney disease;
  • glaucoma;
  • cough with mucus, or cough caused by emphysema or chronic bronchitis;
  • enlarged prostate or urination problems;
  • pheochromocytoma (an adrenal gland tumor);
  • overactive thyroid; 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 chlorpheniramine, dextromethorphan, and methscopolamine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

This medicine can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

How should I take this medicine?

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 take for longer than 7 days in a row. Talk with 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.

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

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.

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

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Since this 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.

What happens if I overdose?

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

What should I avoid while taking this medicine?

Drinking alcohol can increase certain side effects of chlorpheniramine, dextromethorphan, and methscopolamine.

Ask a doctor or pharmacist before using any other cold, cough, allergy, or sleep medicine. Antihistamines and cough suppressants 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 or cough suppressant.

This medication 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.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Chlorpheniramine and methscopolamine can decrease sweating and you may be more prone to heat stroke.

What are the possible side effects of this medicine?

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.

Stop using this medicine and call your doctor at once if you have:

  • fast, slow, or uneven heart rate;
  • pounding heartbeats or fluttering in your chest;
  • mood changes, severe dizziness or anxiety, feeling like you might pass out;
  • severe headache, double vision;
  • fever, ongoing diarrhea or vomiting;
  • little or no urinating;
  • easy bruising or bleeding, unusual weakness; or
  • tremor, seizure (convulsions).

Common side effects may include:

  • dizziness, drowsiness;
  • dry mouth, decreased sense of taste;
  • nausea, diarrhea, constipation, bloating;
  • decreased sweating;
  • blurred vision;
  • sleep problems (insomnia); or
  • feeling nervous, restless, or irritable;.

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.

What other drugs will affect chlorpheniramine, dextromethorphan, and methscopolamine?

Tell your doctor about all medicines you use, 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 chlorpheniramine, dextromethorphan, and methscopolamine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Where can I get more information?

Your pharmacist can provide more information about chlorpheniramine, dextromethorphan, and methscopolamine.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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