On this page · 6 sections
OTC and prescription Expectorants

Guaifenex LA (Oral)

Generic name: guaifenesin

Brand names: Allfen, Altarussin, Amibid LA, Antitussin, Bidex 400, Diabetic Siltussin DAS-Na, Diabetic Tussin EX, Drituss G, Guaifenex G, Guaifenex LA, Mucinex, Robitussin

Last updated December 27, 2025 0 views
Share

Uses for Guaifenex LA

Guaifenesin helps you clear mucus or phlegm (pronounced flem) from your chest when you have congestion due to a cold or flu. It works by thinning the mucus or phlegm in your lungs.

You can get this medicine both over-the-counter (OTC) and with a prescription from your doctor.

Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years old. Using these medicines in very young children might cause serious or possibly life-threatening side effects.

This section was rewritten for readability and reviewed for meaning.

Precautions while using Guaifenex LA

If your cough does not get better after 7 days, or if you have a fever, skin rash, ongoing headache, or sore throat along with the cough, talk to your doctor. These symptoms may indicate other health issues.

This section was rewritten for readability and reviewed for meaning.

Before using Guaifenex LA

In deciding to use a medicine, you and your doctor will need to consider the risks of the medicine compared to the benefits it may provide. For this medicine, consider the following:

Allergies

Inform your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also, let your healthcare provider know if you have any other allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, carefully read the label or package ingredients.

Pediatric

There is no specific information comparing the use of guaifenesin in children to its use in other age groups, but this medicine is not expected to cause different side effects or problems in children compared to adults. However, check with your doctor before giving this medicine to children with a chronic cough, such as asthma, or those with a large amount of mucus or phlegm. Children with these conditions may need a different kind of medicine. Additionally, guaifenesin should not be given to children and infants younger than 2 years of age unless directed by your doctor.

Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years of age. Using these medicines in very young children could lead to serious or possibly life-threatening side effects.

Geriatric

Many medicines have not been studied specifically in older adults. Therefore, it may be unclear whether they work the same way in older people as they do in younger adults. Although there is no specific information comparing the use of guaifenesin in the elderly to other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits and risks before taking this medication while breastfeeding.

Interactions with Medicines

Some medicines should not be used together at all, while in other cases, two different medicines can be used together even if an interaction may happen. In these situations, your doctor may want to adjust the dose or take other precautions. Inform your healthcare provider if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be taken around the time of eating food or specific types of food due to possible interactions. Using alcohol or tobacco with certain medicines may also cause interactions. Talk to your healthcare provider about using your medicine with food, alcohol, or tobacco.

This section was rewritten for readability and reviewed for meaning.

Side Effects of Guaifenex LA

Along with its needed effects, a medicine may cause some unwanted effects. Not all of these side effects may happen, but if they do, they might require medical attention.

Some side effects may occur that usually do not need medical attention. These side effects may disappear during treatment as your body gets used to the medicine. Your health care professional may also provide ways to prevent or lessen some of these side effects. Check with your health care professional if any of the following side effects persist or are bothersome, or if you have any questions about them:

Less common or rare

  • Diarrhea
  • dizziness
  • headache
  • hives
  • nausea or vomiting
  • skin rash
  • stomach pain

Other side effects not listed may also happen in some patients. If you notice any other effects, consult your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

In the U.S.

  • Allfen
  • Altarussin
  • Amibid LA
  • Antitussin
  • Bidex 400
  • Diabetic Siltussin DAS-Na
  • Diabetic Tussin EX
  • Drituss G
  • Guaifenex G
  • Guaifenex LA
  • Mucinex
  • Robitussin

In Canada

  • Balminil Expectorant
  • Balminil Expectorant Sugar-Free
  • Benylin-E
  • Benylin E Extra Strength Chest Congestion
  • Broncho-Grippex Expectorant
  • Resyl
  • Robitussin Extra Strength

Available Dosage Forms:

  • Solution
  • Syrup
  • Liquid
  • Tablet, Extended Release
  • Tablet

Therapeutic Class: Expectorant

This section was rewritten for readability and reviewed for meaning.

Proper use of Guaifenex LA

Drinking plenty of water while taking guaifenesin may help loosen mucus or phlegm in the lungs.

For patients taking the extended-release capsule form of this medicine:

  • Swallow the capsule whole, or open the capsule and sprinkle the contents on soft food such as applesauce, jelly, or pudding and swallow without crushing or chewing.

For patients taking the extended-release tablet form of this medicine:

  • If the tablet has a groove in it, you may carefully break it into two pieces along the groove. Then swallow the pieces whole, without crushing or chewing them.
  • If the tablet does not have a groove, it must be swallowed whole. Do not break, crush, or chew it before swallowing.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For regular (short-acting) oral dosage forms (capsules, oral solution, syrup, or tablets): For cough: Adults—200 to 400 milligrams (mg) every four hours. Children 6 to 12 years of age—100 to 200 mg every four hours. Children 4 to 6 years of age—50 to 100 mg every four hours. Children and infants up to 4 years of age—Use is not recommended.
  • For long-acting oral dosage forms (extended-release capsules or tablets): For cough: Adults—600 to 1200 mg every twelve hours. Children 6 to 12 years of age—600 mg every twelve hours. Children 4 to 6 years of age—300 mg every twelve hours. Children and infants up to 4 years of age—Use is not recommended.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Frequently asked questions

  • Does Mucinex help you get pregnant?
  • What cold medicine can you take with diabetes?
  • Does Mucinex help with Covid?
  • What is the dose for an adult for Robitussin DM? How many times a day?

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
General medicine information Consumer-friendly language

Content is provided for education and is not medical advice. See our medical disclaimer.