Guaifenesin is an expectorant. Guaifenesin loosens phlegm and increases the lubrication of your lungs allowing for a productive cough and decreased chest congestion.

Guaifenesin is used to reduce chest congestion caused by the common cold, infections, or allergies.

Guaifenesin may also be used for purposes other than those listed in this medication guide.

Take guaifenesin exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water. Drink plenty of extra fluids while you are taking this medication. Extra fluids may help to relieve chest congestion.

Take guaifenesin with food if it upsets your stomach.

Do not crush or chew the tablets. Swallow them whole or break them in half where they are scored to make them easier to swallow.

The capsules may be swallowed whole, or they may be opened and the contents sprinkled on soft food such as pudding or applesauce then swallowed whole without crushing or chewing.

To ensure that you get a correct dose, measure the liquid form of guaifenesin with a special dose-measuring spoon or cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

Store guaifenesin at room temperature away from moisture, heat, and direct sunlight.

There are no known interactions between guaifenesin and other medicines, although the possibility exists. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Use caution when driving, operating machinery, or performing other hazardous activities. Guaifenesin may cause dizziness. If you experience dizziness, avoid these activities.

An overdose of guaifenesin is unlikely to occur. If you do suspect an overdose, call an emergency room or poison control center near you.

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only your next regularly scheduled dose. Do not take a double dose of this medication.

Drink plenty of extra fluids while you are taking this medication. Extra fluids may help to relieve chest congestion.

Do not crush or chew the tablets. Swallow them whole or break them in half where they are scored to make them easier to swallow.

Talk to your doctor before taking guaifenesin if you have other medical conditions or if you take other medicines.

Guaifenesin is in the FDA pregnancy category C. This means that it is not known whether guaifenesin will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant.

It is also not known whether guaifenesin passes into breast milk. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

Guaifenesin has not been approved by the FDA for use by children younger than 2 years of age.

Your pharmacist has additional information about guaifenesin written for health professionals that you may read.

Guaifenesin is available with a prescription generically and under several brand names. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

• Fenesin 600 mg—light-blue, scored tablets

• Humibid L.A. 600 mg—light-green, scored capsules

• Humibid Pediatric Capsules 300 mg—green/clear capsules with white beads

• Organidin NR 200 mg guaifenesin—round, scored, rose-colored tablets

• Organidin NR Liquid, 100 mg guaifenesin per 5 mL (1 teaspoon)—clear, amber liquid