Guaifenesin (glyceryl guaiacolate) has the chemical name 3-(2-methoxyphenoxy)-1,2-propanediol. Its molecular formula is C₁₀H₁₄O₄ with a molecular weight of 198.21. It is a white or slightly gray crystalline substance with a slightly bitter aromatic taste. One gram dissolves in 20 mL water at 25°C; it is freely soluble in ethanol. Guaifenesin is readily absorbed from the GI tract and is rapidly metabolized and excreted in the urine. Guaifenesin has a plasma half-life of one hour. The major urinary metabolite is ?-(2-methoxyphenoxy) lactic acid.

ORGANIDIN® NR (guaifenesin) is an expectorant available for oral administration as:

Tablets - each containing 200 mg guaifenesin, USP.

Other ingredients: Corn starch, croscarmel-lose sodium, FD&C Red No. 40, magnesium stearate, microcrystalline cellulose.

Liquid - each teaspoonful (5 mL) containing 100 mg guaifenesin, USP.

Other ingredients: Caramel, citric acid, flavor (raspberry), glycerin, propylene gly-col, purified water, saccharin sodium, sodium benzoate, sorbitol solution.

If your doctor has directed you to use this medication, remember that he or she has judged that the benefit to you is greater than the risk of side effects. Most people using this medication do not have serious side effects.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

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

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as emphysema, chronic bronchitis, asthma, smoker's cough), cough with blood or large amounts of mucus.

Liquid forms of this product may contain sugar and/or alcohol. Caution is advised if you have diabetes, liver disease, or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely

The liquid forms and powder packets of this medication may contain aspartame. If you have phenylketonuria (PKU) or any other condition that requires you to restrict your intake of aspartame (or phenylalanine), consult your doctor or pharmacist about using this product safely.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if guaifenesin passes into breast milk. Discuss the risks and benefits with your doctor before breast-feeding.