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Generic Name: guaifenesin and phenylephrine (gwye FEN e sin and FEN il EFF rin)
Brand Name: Aldex G, Aquatab D, Deconex, Despec, Donatussin Drops, D-Phen 1000, Duravent PE, Genexa LA, Gilphex TR, J-Max, Liquibid-PD, Lusair, MucaphEd, Mucinex Children's Cold, PE-Guai, Prolex D, Rescon-GG, Robitussin Head & Chest Congestion, Sudafed PE Non-Drying Sinus, Supress-PE, Triaminic Chest & Nasal Congestion, Xpect-PE
What is Duomax (guaifenesin and phenylephrine)?
There are many brands and forms of guaifenesin and phenylephrine available and not all brands are listed on this leaflet.
Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.
Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).
Guaifenesin and phenylephrine is a combination medicine used to treat stuffy nose and sinus congestion, and to reduce chest congestion caused by the common cold or flu.
Guaifenesin and phenylephrine may also be used for purposes not listed in this medication guide.
What is the most important information I should know about Duomax (guaifenesin and phenylephrine)?
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.
What should I discuss with my healthcare provider before taking Duomax (guaifenesin and phenylephrine)?
You should not use guaifenesin and phenylephrine if you are allergic to it.
Do not use guaifenesin and phenylephrine 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.
Ask a doctor or pharmacist if it is safe for you to take this medication if you have:
high blood pressure, heart disease, coronary artery disease;
overactive thyroid; or
enlarged prostate or problems with urination.
It is not known if this medication may be harmful to an unborn baby. Do not use this medicine without medical advice if you are pregnant.
Guaifenesin and phenylephrine may pass into breast milk and may harm a nursing baby. Decongestants may also slow breast milk production. Do not use this medicine without medical advice if you are breast-feeding a baby.
Artificially sweetened liquid medicine may contain phenylalanine. Check the medication label if you have phenylketonuria (PKU).
How should I take Duomax (guaifenesin 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. 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 cough or cold medicine to a child. Death can occur from the misuse of cough or cold medicine in very young children.
Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole.
Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication.
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.
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 Duomax (guaifenesin and phenylephrine)?
This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Drinking alcohol can increase certain side effects of guaifenesin and phenylephrine.
Ask a doctor or pharmacist before using any other cough, cold, or allergy medicine. Guaifenesin and phenylephrine are contained in many combination medicines. Taking certain products together can cause you to get too much of a certain drug.
Duomax (guaifenesin and phenylephrine) side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using guaifenesin and phenylephrine and call your doctor at once if you have:
fast, pounding, or uneven heartbeat; or
severe anxiety or nervousness.
Common side effects may include:
dry mouth, nose, or throat;
upset stomach, loss of appetite, vomiting;
feeling excited or restless (especially in children);
sleep problems (insomnia); or
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.
See also: Side effects (in more detail)
What other drugs will affect Duomax (guaifenesin 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.
Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking guaifenesin and phenylephrine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.
More about Duomax (guaifenesin / phenylephrine)
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- Support Group
- 0 Reviews – Add your own review/rating
- Drug class: upper respiratory combinations
Related treatment guides
Where can I get more information?
- Your pharmacist can provide more information about guaifenesin 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.
- Disclaimer: 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 1996-2012 Cerner Multum, Inc. Version: 13.07. Revision Date: 2015-10-20, 3:05:44 PM.