dextromethorphan and phenylephrine

What is the most important information I should know about dextromethorphan and phenylephrine?

Do not use dextromethorphan and phenylephrine 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.

What is dextromethorphan and phenylephrine?

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

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

Dextromethorphan and phenylephrine is a combination medicine used to treat cough, stuffy nose, and sinus congestion caused by allergies, the common cold, or the flu.

Dextromethorphan and phenylephrine may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking dextromethorphan and phenylephrine?

Do not use dextromethorphan and phenylephrine 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.

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have:

• high blood pressure;
• coronary artery disease (hardened arteries),
• diabetes;
• glaucoma;
• epilepsy or other seizure disorder;
• enlarged prostate or urination problems;
• pheochromocytoma (an adrenal gland tumor); or
• cough with mucus, or cough caused by emphysema or chronic bronchitis.

Artificially sweetened cold medicine may contain phenylalanine. If you have phenylketonuria (PKU), check the medication label to see if the product contains phenylalanine.

How should I take dextromethorphan and phenylephrine?

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. This medicine is usually taken only for a short time until your symptoms clear up.

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

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.

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?

What should I avoid while taking dextromethorphan and phenylephrine?

What are the possible side effects of dextromethorphan and phenylephrine?

• fast or uneven heart rate;
• severe dizziness or anxiety, feeling like you might pass out;
• severe headache;
• mood changes;
• fever; or
• dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, chest pain, uneven heartbeats, seizure).

Common side effects may include:

• diarrhea;
• dizziness, drowsiness;
• 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 dextromethorphan and phenylephrine?

Ask a doctor or pharmacist before using this medicine 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.

Where can I get more information?

Your pharmacist can provide more information about dextromethorphan and phenylephrine.

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.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2023 Cerner Multum, Inc. Version: 1.03. Revision date: 1/5/2014.