Guaifenesin/phenylephrine (By mouth)
Guaifenesin (gwye-FEN-e-sin), Phenylephrine (fen-il-EF-rin)
Treats cough and stuffy nose caused by hay fever or the common cold. Also thins mucus to make a cough more productive. This medicine is a combination of an expectorant and a decongestant.
GFN 1200/Phenylephrine 40, Crantex, Xpect-PE, Xedec II, MyDocs, Prolex-D, Prolex PD, Pendex, Simuc, Reluri, Liquibid PD-R, Deconex IR, Maxiphen, Ambi 10PEH/400GFN, Refenesen PE
There may be other brand names for this medicine.
When This Medicine Should Not Be Used
You should not use this medicine if you have had an allergic reaction to guaifenesin or phenylephrine, or to other cold medicines, diet pills, or medicines to treat asthma, bronchitis, or attention deficit disorder. You should not use this medicine if you have used an MAO inhibitor (MAOI) such as Eldepryl®, Marplan®, Nardil®, or Parnate® within the past 14 days. You should not use this medicine if you have high blood pressure, heart or blood vessel disorders, or overactive thyroid. Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years old. Using these medicines in very young children might cause serious or possibly life-threatening side effects.
How to Use This Medicine
Long Acting Tablet, Tablet, Syrup, Liquid, Solution, Capsule, 12 Hour Tablet
- Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
- If you are using this medicine without a prescription, follow the instructions on the medicine label.
- Swallow the capsule or tablet whole. Do not crush, break, or chew it.
- Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
- You may take this medicine with food if it upsets your stomach.
If a dose is missed:
- If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not refrigerate or freeze the liquid form of this medicine.
- Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
- Keep all medicine away from children and never share your medicine with anyone.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Make sure your doctor knows if you are also using a beta-blocker such as atenolol, labetalol, metoprolol, propranolol, timolol, Inderal®, or Toprol®. Tell your doctor if you are using digoxin (Lanoxin®), guanethidine (Ismelin®), mecamylamine (Inversine), methyldopa (Aldomet®), or reserpine. Your doctor should know if you use medicine for depression such as amitriptyline, doxepin, nortriptyline, Elavil®, Pamelor®, or Sinequan®.
Warnings While Using This Medicine
- Make sure your doctor knows if you are pregnant or breastfeeding.
- Tell your doctor if you have diabetes, thyroid problems, high blood pressure, glaucoma, an enlarged prostate, or a history of heart disease.
- Older adults may be more likely to have side effects from this medicine.
- Do not give this medicine to a child under 12 years of age, unless your doctor tells you to.
- Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.
Possible Side Effects While Using This Medicine
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Fast, pounding, or uneven heartbeat.
- Feeling extremely confused, fearful, or anxious.
- High fever, skin rash, sore throat, ongoing headache.
- Lightheadedness or fainting.
- No improvement in your symptoms after using the medicine for 7 days.
- Seizure, hallucinations, vomiting.
- Shallow breathing, pale skin.
- Unusual weakness, tremors, or shaking.
If you notice these less serious side effects, talk with your doctor:
- Anxiety, fear, depression, nervousness.
- Dizziness, trouble sleeping.
- Feelings of excitement, elevated mood, or increased energy.
- Loss of appetite.
- Mild fever or headache.
If you notice other side effects that you think are caused by this medicine, tell your doctor
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
- Last Reviewed on 06/12/2013
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This page was last updated: September 18, 2013