Prescription Drugs

Similar medicines derived from the guaiac tree were in use as a generic remedy by Native Americans when explorers reached North America in the 1500s, but guaifenesin was first approved by the Food and Drug Administration (FDA) in 1952.

Guaifenesin Dosage

A person’s age can affect the dose of guaifenesin that should be taken, as can weight when giving the medication to children. In general, adults should not take more than 2400 mg in 24 hours; children ages 6 to 11 should not take more than 1200 mg in 24 hours. It is important to drink plenty of water during treatment with guaifenesin.

An Introduction to Dosing With Guaifenesin

The recommended dosage of guaifenesin (an active ingredient in Mucinex®, Robitussin®, and many other medications) will vary, depending on a number of factors, including:

  •  The particular product
  •  Your age
  •  The medical condition being treated
  •  How you respond to guaifenesin
  •  Other medications you are taking
  •  Other medical conditions you may have.

As is always the case, do not adjust this amount unless your healthcare provider specifically tells you to do so.

Guaifenesin Dosage for Adults

Most guaifenesin products are approved for use in adults and children age 12 and older. Depending on the particular product, a typical guaifenesin dose is 200 to 400 mg every 4 hours (not to exceed 2400 mg per day) for immediate-release products and 600 to 1200 mg every 12 hours (not to exceed 2400 mg in 24 hours) for extended-release products.

Keep in mind that these are general guidelines and specific medications may have different directions. Be sure to follow the directions for your particular product.

Guaifenesin Dosing for Children

In general, guaifenesin can be dosed by age or by weight for children. Based on weight, a standard recommended dosage is 0.35 mg per kg per day (0.16 mg per pound per day), divided into smaller doses given every four to six hours.

Based on age, dosing guidelines for immediate-release guaifenesin are as follows:

  •  Age 4 to 5 years: 50 to 100 mg every 4 hours, not to exceed 600 mg in 24 hours
  •  Age 6 to 11 years old: 100 to 100 mg every 4 hours, not to exceed 1200 mg in 24 hours.

Extended-release guaifenesin (Mucinex) is not approved for use in children under the age of 12.

Cold or cough medications (including guaifenesin) should not be used in children under four years old, unless your child’s healthcare provider specifically recommends such products. Since the labels for cough and cold products do not currently list appropriate dosages for children under the age of four, be sure to ask your healthcare provider for the correct dosage for your particular child.

What Is the Dosage for Other Uses?

For any use other than to make coughs more productive, it is recommended that you consult your healthcare provider before taking guaifenesin.

General Information on Taking Guaifenesin

Considerations to keep in mind during treatment with guaifenesin include the following:

  •  This medication comes in different forms, including tablets, long-acting tablets, capsules, and syrup. It is taken by mouth every 4 to 12 hours, depending on the particular product.
  •  You can take a dose of guaifenesin with food or on an empty stomach. If the medication bothers your stomach, try taking it with a little food.
  •  Because several different guaifenesin products are available, be sure to follow the instructions for your particular product.
  •  Extended-release guaifenesin tablets (Mucinex) must be swallowed whole. Do not break or crush them.
  •  Be sure to drink plenty of water or other fluids while taking guaifenesin.
  •  For the medication to work properly, it must be taken as directed.
  • If you are unsure about anything related to your guaifenesin dosage, please talk with your doctor, nurse, or pharmacist.

Why is this medication prescribed?

Guaifenesin is used to relieve chest congestion . Guaifenesin may help control symptoms but does not treat the cause of symptoms or speed recovery. Guaifenesin is in a class of medications called expectorants. It works by thinning the mucus in the air passages to make it easier to cough up the mucus and clear the airways.

How should this medication be used?

Guaifenesin comes as a tablet, a capsule, an extended-release (long-acting) tablet, dissolving granules, and a syrup (liquid) to take by mouth. The tablets, capsules, dissolving granules, and syrup are usually taken with or without food every 4 hours as needed. The extended-release tablet is usually taken with or without food every 12 hours. Follow the directions on the package or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take guaifenesin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Guaifenesin comes alone and in combination with antihistamines, cough suppressants, and decongestants. Ask your doctor or pharmacist for advice on which product is best for your symptoms. Check nonprescription cough and cold product labels carefully before using two or more products at the same time. These products may contain the same active ingredient(s) and taking them together could cause you to receive an overdose. This is especially important if you will be giving cough and cold medications to a child.

Nonprescription cough and cold combination products, including products that contain guaifenesin, can cause serious side effects or death in young children. Do not give these products to children younger than 4 years of age. If you give these products to children 4 to 11 years of age, use caution and follow the package directions carefully.

If you are giving guaifenesin or a combination product that contains guaifenesin to a child, read the package label carefully to be sure that it is the right product for a child of that age. Do not give guaifenesin products that are made for adults to children.

Before you give a guaifenesin product to a child, check the package label to find out how much medication the child should receive. Give the dose that matches the child’s age on the chart. Ask the child’s doctor if you don’t know how much medication to give the child.

If you are taking the liquid, do not use a household spoon to measure your dose. Use the measuring spoon or cup that came with the medication or use a spoon made especially for measuring medication.

Swallow the extended-release tablets whole with a full glass of water. Do not break, crush, or chew them.

If you are taking the dissolving granules, empty the entire contents of the packet onto your tongue and swallow.

If your symptoms do not improve within 7 days or if you also have a high fever, a rash, or a headache that does not go away, call your doctor.

Are there other uses for this medicine?

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.