Guaifenesin Risks, Warnings, and Complications

Precautions Before Starting Guaifenesin

Tell your healthcare professional if you are allergic to guaifenesin, any of the active or inactive ingredients in guaifenesin products, or any other drugs.

Give your healthcare professional a complete medical history. Guaifenesin may not be right for people with certain medical conditions such as asthma, emphysema, chronic bronchitis, and other breathing illnesses. If you are taking the dissolving granules of guaifenesin, tell your doctor if you have a medical problem called phenylketonuria. Also, tell your doctor if you have low magnesium or kidney disease.

Give your health care professional a complete list of your medications, including prescription drugs, nonprescription drugs, vitamins, supplements, and herbal products. This can help avoid possible drug interactions.

Tell your doctor if you are pregnant, could be pregnant, are planning a pregnancy or are breastfeeding (it is unclear if the medicine is excreted into breast milk).

Precautions During Use of Guaifenesin

Make sure you drink enough fluids while on guaifenesin. This medicine will help relieve your symptoms but will not cure your condition. If you continue having symptoms 7 days after starting guaifenesin or have a high fever, rash, and headache, contact your doctor. Tell your doctor if you become pregnant while on guaifenesin.

Guaifenesin Drug Interactions

Guaifenesin can have possible interactions with other drugs. This can affect how well the medications work. Interactions between guaifenesin and other medicines can also increase the risk of severe adverse effects. 

Give your doctor or pharmacist a complete list of your medications, including prescription drugs, nonprescription (over-the-counter) drugs, dietary supplements, and herbal products. Also, tell your healthcare provider if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medicines.