What is Amidal (Guaifenesin Phenylephrine)?
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).
The combination of guaifenesin and phenylephrine is 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 other purposes not listed in this medication guide.
What is the most important information I should know about Amidal (Guaifenesin Phenylephrine)?
There are many brands and forms of guaifenesin and phenylephrine available and not all brands are listed on this leaflet.
Do not give this medication to a child younger than 2 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.
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 a certain drug. Read the label of any other medicine you are using to see if it contains a decongestant or expectorant.
What should I discuss with my healthcare provider before taking Amidal (Guaifenesin Phenylephrine)?
Do not use this medication if you are allergic to guaifenesin or phenylephrine, or to other decongestants, diet pills, stimulants, or ADHD medications.
Do not use a cough or cold medicine if you have used an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), o 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.
Ask a doctor or pharmacist if it is safe for you to take this medication if you have:
- heart disease or high blood pressure
- a thyroid disorder
- circulation problems
- 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 medication without your doctor’s advice if you are pregnant.
This medication passes into breast milk and 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.
Amidal Side Effects
What are the possible side effects of Amidal (Guaifenesin Phenylephrine)?
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:
- fast, pounding, or uneven heartbeat
- severe dizziness, anxiety, restless feeling, or nervousness
- easy bruising or bleeding, unusual weakness, fever, chills, body aches, flu symptoms
- increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure)
- nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)
Less serious side effects may include:
- nausea, vomiting, upset stomach, loss of appetite
- warmth, tingling, or redness under your skin
- feeling excited or restless
- sleep problems (insomnia)
- skin rash or itching
- headache; 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.
What other drugs affect Amidal (Guaifenesin Phenylephrine)?
Ask a doctor or pharmacist if it is safe for you to take guaifenesin and phenylephrine if you are also using any of the following drugs:
- medicines to treat high blood pressure
- a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others; or
- an antidepressant such as amitriptyline (Elavil, Vanatrip), doxepin (Sinequan), desipramine (Norpramin), imipramine (Janimine, Tofranil), nortriptyline (Pamelor), and others
This list is not complete and there may be other drugs that can interact with guaifenesin and phenylephrine. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.
What should I avoid while taking Amidal (Guaifenesin Phenylephrine)?
Avoid drinking alcohol while you are taking this medicine.
Do not use any other over-the-counter cough or cold medication without first asking your doctor or pharmacist. Guaifenesin and phenylephrine are contained in many medicines available over the counter. If you take certain products together you may accidentally take too much of a certain drug. Read the label of any other medicine you are using to see if it contains a decongestant or expectorant.
Avoid taking this medication with diet pills, caffeine pills, or other stimulants (such as ADHD medications). Taking a stimulant together with a decongestant can increase your risk of unpleasant side effects.
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.
How should I take Amidal (Guaifenesin Phenylephrine)?
Use this medication 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. 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 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, break, or open a controlled-release, delayed-release, or extended-release tablet or capsule. Swallow the pill whole. It is specially made to release medicine slowly in the body. Breaking or opening the pill would cause too much of the drug to be released at one time.
Take guaifenesin and phenylephrine with food if it upsets your stomach.
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.
Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication.
What happens if I overdose on Amidal (Guaifenesin Phenylephrine)?
Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include nausea, vomiting, numbness or tingly feeling, dizziness, and feeling restless or nervous.
What happens if I miss a dose of Amidal (Guaifenesin Phenylephrine)?
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.
Edited from everydayhealth.com