Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.

Pseudoephedrine 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 pseudoephedrine is used to treat stuffy nose, sinus congestion, and cough caused by allergies or the common cold.

Guaifenesin and pseudoephedrine may also be used for purposes not listed in this medication guide.

Do not give this medication to a child younger than 4 years old. Always\s 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 furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.

Ask a doctor or pharmacist before using any other cold, cough, or allergy medicine. Guaifenesin and pseudoephedrine are contained in many combination medicines. Taking certain products together can cause you to get too much of a certain drug. Check the label to see if a medicine contains guaifenesin or pseudoephedrine.

You should not use this medication if you are allergic to guaifenesin or pseudoephedrine, 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, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.

Ask a doctor or pharmacist if it is safe for you to take this medicine if you have:

• heart disease or high blood pressure;

• diabetes; or

• a thyroid disorder.

It is not known whether guaifenesin and pseudoephedrine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Guaifenesin and pseudoephedrine may pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Artificially sweetened liquid cough or cold medicine may contain phenylalanine. If you have phenylketonuria (PKU), check the medication label to see if the product contains phenylalanine.