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Phenylephrine/ guaifenesin

Generic Name: phenylephrine/guaifenesin (FEN-il-EF-rin/gwye-FEN-e-sin and KLOR-fen-IR-a-meen/FEN-il-EF-rin/METH-skoe-POL-a-meen)
Brand Name: SymPak

Phenylephrine/ guaifenesin is used for:

Relieving nasal and chest congestion, sneezing, runny nose, and itchy, watery eyes due to colds, flu, or allergies. It is also used to make a dry cough more productive and less frequent. It may also be used for other conditions as determined by your doctor.

Phenylephrine/guaifenesin is a combination pack containing a morning dose and an evening dose. The morning dose has a decongestant and expectorant. The evening dose has an antihistamine, decongestant, and anticholinergic. The decongestant works by shrinking swollen tissue in the nose. The expectorant works by thinning mucus in the lungs. The antihistamine works by blocking histamine, a substance in the body that causes sneezing, runny nose, and watery eyes. The anticholinergic works by drying mucous membranes in the nose and chest.

Do NOT use phenylephrine/ guaifenesin if:

  • you are allergic to any ingredient in phenylephrine/guaifenesin
  • you are pregnant or breast-feeding
  • you are taking droxidopa, furazolidone, sodium oxybate (GHB), or a monoamine oxidase inhibitor (MAOI) (eg, phenelzine), or if you have taken an MAOI within the past 14 days
  • you have severe heart blood vessel problems, severe high blood pressure, narrow-angle glaucoma, difficulty urinating due to enlarged prostate, peptic ulcer, or uncontrolled bleeding
  • you are having an asthma attack

Contact your doctor or health care provider right away if any of these apply to you.

Before using phenylephrine/ guaifenesin:

Some medical conditions may interact with phenylephrine/guaifenesin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have bladder blockage, blood vessel problems (eg, hardening of the arteries), diabetes, an enlarged prostate, glaucoma or increased pressure in the eye, heart problems (eg, irregular heartbeat, heart failure), heart blood vessel problems, high blood pressure, inflammation of the esophagus from reflux disease, kidney problems, lung or breathing problems (eg asthma, sleep apnea), a hiatal hernia, an adrenal gland tumor (pheochromocytoma), myasthenia gravis (muscle weakness), stomach or bowel problems (eg, constipation, inflammation, motility problems, blockage), trouble sleeping, or an overactive thyroid
  • if you have a history of alcohol abuse
  • if you take potassium chloride tablets

Some MEDICINES MAY INTERACT with phenylephrine/guaifenesin. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Droxidopa or sodium oxybate (GHB) because the risk of severe drowsiness, breathing problems, seizures, irregular heartbeat, or heart attack may be increased
  • Beta-blockers (eg, propranolol), catechol-O-methyltransferase (COMT) inhibitors (eg, tolcapone), furazolidone , MAOIs (eg, phenelzine), or tricyclic antidepressants (eg, amitriptyline) because they may increase the risk of phenylephrine/guaifenesin's side effects
  • Bromocriptine because the risk of its side effects may be increased by phenylephrine/guaifenesin
  • Guanadrel, guanethidine, mecamylamine, methyldopa, reserpine, or other medicine for high blood pressure because their effectiveness may be decreased by phenylephrine/guaifenesin

This may not be a complete list of all interactions that may occur. Ask your health care provider if phenylephrine/guaifenesin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use phenylephrine/ guaifenesin:

Use phenylephrine/guaifenesin as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Take phenylephrine/guaifenesin by mouth with or without food.
  • Swallow phenylephrine/guaifenesin whole. Do not break, crush, or chew before swallowing. Some brands of phenylephrine/guaifenesin may be broken in half before taking. If you have difficulty swallowing the whole tablet, ask your pharmacist if your brand of medicine may be broken in half.
  • This product contains 2 different tablets; one for the morning and one for the evening. Be sure you understand how to take phenylephrine/guaifenesin. Check with your doctor or pharmacist if you are not sure which tablet to take in the morning or in the evening.
  • If you miss a dose of phenylephrine/guaifenesin and you are taking it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use phenylephrine/guaifenesin.

Important safety information:

  • Phenylephrine/guaifenesin may cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use phenylephrine/guaifenesin with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using phenylephrine/guaifenesin; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
  • The risk of dizziness, nervousness, and trouble sleeping may be greater if you take phenylephrine/guaifenesin in high doses or for a long time. Do NOT take more than the recommended dose without checking with your doctor.
  • If your cough or other symptoms persist for more than 1 week, come back, or if you also have fever, rash, or persistent headache, check with your doctor.
  • Phenylephrine/guaifenesin may interfere with certain lab test results. Be sure your doctors and laboratory personnel know that you are taking phenylephrine/guaifenesin.
  • Tell your doctor or dentist that you take phenylephrine/guaifenesin before you receive any medical or dental care, emergency care, or surgery.
  • Phenylephrine/guaifenesin may cause dry mouth. To relieve dry mouth, suck on sugarless hard candy or ice chips, chew sugarless gum, drink water, or use a saliva substitute.
  • Phenylephrine/guaifenesin may reduce sweating. Do not become overheated in hot weather or during exercise or other activities because heatstroke may occur.
  • Phenylephrine/guaifenesin has phenylephrine in it. Before you start any new medicine, check the label to see if it has phenylephrine in it too. If it does or if you are not sure, check with your doctor or pharmacist.
  • Do not take diet or appetite control medicines while you are taking phenylephrine/guaifenesin without checking with your doctor.
  • Diabetes patients - Phenylephrine/guaifenesin may affect your blood sugar. Check blood sugar levels closely and ask your doctor before adjusting the dose of your diabetes medicine.
  • Use phenylephrine/guaifenesin with caution in the ELDERLY; they may be more sensitive to its effects.
  • Phenylephrine/guaifenesin should be used with extreme caution in CHILDREN younger than 6 years old; safety and effectiveness in these children have not been confirmed.
  • Caution is advised when using phenylephrine/guaifenesin in CHILDREN; they may be more sensitive to its effects, especially excitability.
  • PREGNANCY and BREAST-FEEDING: It is not known if phenylephrine/guaifenesin can cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using phenylephrine/guaifenesin while you are pregnant. Phenylephrine/guaifenesin is found in breast milk. Do not breast-feed while taking phenylephrine/guaifenesin.

Possible side effects of phenylephrine/ guaifenesin:

All medicines may cause side effects, but many people have no, or minor side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Blurred vision; dizziness; drowsiness; dry mouth, nose, or throat; excitability or irritability (especially in children); giddiness; headache; lightheadedness; nausea; nervousness; trouble sleeping; unusual tiredness or weakness.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); fast or irregular heartbeat; flushing; hallucinations; mental or mood changes; seizures severe drowsiness; tremor; vomiting.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately.

Proper storage of phenylephrine/guaifenesin:

Store phenylephrine/guaifenesin in a tightly closed container between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep phenylephrine/guaifenesin out of the reach of children and away from pets.

General information:

  • If you have any questions about phenylephrine/guaifenesin, please talk with your doctor, pharmacist, or other health care provider.
  • Phenylephrine/guaifenesin is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about phenylephrine/guaifenesin. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: June 3, 2015