In this Article

• What is guaifenesin and phenylephrine (Entex La)?
• What are the possible side effects of guaifenesin and phenylephrine?
• What is the most important information I should know about guaifenesin and phenylephrine?
• What should I discuss with my healthcare provider before taking guaifenesin and phenylephrine?
• How should I take guaifenesin and phenylephrine?
• What happens if I miss a dose?
• What happens if I overdose?
• What should I avoid while taking guaifenesin and phenylephrine?
• What other drugs will affect guaifenesin and phenylephrine?
• Where can I get more information?

What should I discuss with my healthcare provider before taking guaifenesin and phenylephrine?

You should 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 guaifenesin and phenylephrine 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. Serious, life threatening side effects can occur if you use guaifenesin and phenylephrine 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;
• diabetes;
• circulation problems;
• glaucoma;
• 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.

How should I take guaifenesin and phenylephrine?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or 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 an extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may 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.

Store at room temperature away from moisture and heat.