What is dextromethorphan and guaifenesin?
Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger cough
reflex.
Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it
easier to cough out through your mouth.
The combination of dextromethorphan and guaifenesin is used to treat cough and chest
congestion caused by the common cold, infections, or allergies.
Dextromethorphan will not treat a cough that is caused by smoking, asthma, or emphysema.
Dextromethorphan and guaifenesin may also be used for other purposes not listed in this
medication guide.
What should I discuss with my healthcare provider before taking dextromethorphan and guaifenesin?
Do not use a cough or cold medicine if you have used an MAO inhibitor such as
isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or
tranylcypromine (Parnate) within the past 14 days. Serious, life-threatening side effects can occur if
you take cough or cold medicine before the MAO inhibitor has cleared from your body.
Before taking dextromethorphan and guaifenesin, tell your doctor if you are allergic to any
drugs, or if you have emphysema or chronic bronchitis. If you have any of these conditions, you may
not be able to use this medication, or you may need a dosage adjustment or special tests during
treatment.
FDA pregnancy category C. It is not known whether dextromethorphan and guaifenesin is
harmful to an unborn baby. Before you take this medication, tell your doctor if you are pregnant or plan
to become pregnant during treatment.
It is not known whether this medication passes into breast milk or if it could harm a nursing
baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
Artificially-sweetened liquid forms of cold 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.
How should I take dextromethorphan and guaifenesin?
Take this medication exactly as it has been prescribed by your doctor. Do not use the
medication in larger amounts, or use it for longer than recommended. Follow the directions on your
prescription label. Cold medicine is usually taken only for a short time until your symptoms clear up.
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 this medicine 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.
Do not crush, chew, or break an extended-release tablet. Swallow the pill whole. It is
specially made to release medicine slowly in the body. Breaking the pill would cause too much of the
drug to be released at one time.
Dextromethorphan and guaifenesin granules should be sprinkled directly onto the tongue and
swallowed right away.
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 a cold
medicine within the past few days.
Store this medicine at room temperature, away from heat, light, and moisture.
What happens if I miss a dose of dextromethorphan and guaifenesin?
Since cough or cold 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.
Where can I get more information about dextromethorphan and guaifenesin?
Your pharmacist has information about dextromethorphan and guaifenesin written for health professionals that you may read.
What are the possible side effects of dextromethorphan and guaifenesin?
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 this medication and call your doctor at once if you have any of these serious side
effects:
-
severe dizziness, anxiety, restless feeling, or nervousness;
-
confusion, hallucinations; or
-
slow, shallow breathing.
Less serious side effects may include:
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. You may report side effects to FDA at 1-800-FDA-1088.
What is the most important information I should know about dextromethorphan and guaifenesin?
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 a cough or cold medicine if you have used an MAO inhibitor such as
isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or
tranylcypromine (Parnate) within the past 14 days. Serious, life-threatening side effects can occur if
you take cough or cold medicine before the MAO inhibitor has cleared from your body.
Do not use any other over-the-counter cough or cold 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 or guaifenesin.
Dextromethorphan will not treat a cough that is caused by smoking, asthma, or emphysema.
What should I avoid while taking dextromethorphan and guaifenesin?
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 drinking alcohol. It can increase some of the side effects of this medication.
Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without
your doctor's advice. Taking a stimulant together with cough or cold medicine can increase your risk
of unpleasant side effects.
Do not use any other over-the-counter cough or cold medication without first asking your
doctor or pharmacist. Dextromethorphan and guaifenesin are contained in many medicines available
over the counter. 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 or guaifenesin.
What other drugs will affect dextromethorphan and guaifenesin?
Before taking this medication, 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
-
an antidepressant 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 may be other drugs that can interact with
dextromethorphan and guaifenesin. 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.
What happens if I have an overdose of dextromethorphan and guaifenesin?