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Guaifenesin-DM NR Prescribing Information

Package insert / product label
Generic name: guaifenesin and dextromethorphan hydrobromide
Dosage form: liquid
Drug class: Upper respiratory combinations

Medically reviewed by Last updated on Mar 25, 2024.

Guaifenesin-DM NR Description

Guaifenesin-DM NR Liquid is a clear yellow liquid with a raspberry flavor.
Each 5 mL (1 teaspoonful) contains:
Guaifenesin 100 mg.
Dextromethorphan Hydrobromide 10 mg.

Other Ingredients: Citric Acid, D&C Yellow No. 10, FD&C Red No. 40, Glycerin, Methylparaben, Propylene Glycol, Raspberry Flavor, Saccharin Sodium, Sodium Benzoate, Sorbitol Solution, Water. It may contain Sodium Citrate. 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, colorless crystalline substance with a slightly bitter aromatic taste. One gram dissolves in 20 mL water at 25°C; 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 halflife of one hour. The major urinary metabolite is beta-(2-methoxyphenoxy) lactic acid.

Guaifenesin-DM NR - Clinical Pharmacology

GUAIFENESIN-DM NR LIQUID combines the expectorant, guaifenesin and the cough suppressant, dextromethorphan hydrobromide. Guaifenesin is an expectorant, the action of which promotes or facilitates the removal of secretions from the respiratory tract. By increasing sputum volume and making sputum less viscous, guaifenesin facilitates expectoration of retained secretions. Dextromethorphan is a synthetic nonopioid cough suppressant, the dextro isomer of the codeine analogue of levorphanol. Dextromethorphan acts centrally to elevate the threshold for coughing, but does not have addictive, analgesic or sedative actions and does not produce respiratory depression with usual doses.

Indications and Usage for Guaifenesin-DM NR

Temporarily relieves cough due to minor throat and bronchial irritation as may occur with the common cold or inhaled irritants. Calms the cough control center and relieves coughing. Helps loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus, drain bronchial tubes, and make coughs more productive.


Hypersensitivity to any of the ingredients. The use of dextromethorphan-containing products is contraindicated in patients receiving monoamine oxidase inhibitors (MAOIs).


Carcinogenesis, Mutagenesis, Impairment of Fertility: Animal studies to assess the long-term carcinogenic and mutagenic potential or the effect on fertility in animals or humans of GUAIFENESIN-DM NR Liquid have not been performed.

Teratogenic Effects-Pregnancy Category C: Animal reproduction studies have not been conducted. Safe use in pregnancy has not been established relative to possible adverse effects on fetal development. Therefore, this product should not be used in pregnant patients, unless in the judgment of the physician, the potential benefits outweigh possible hazards.

Nursing Mothers: It is not known whether guaifenesin or dextromethorphan is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when these products are administered to a nursing woman and a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Laboratory Test Interactions: Guaifenesin or its metabolites may cause color interference with the VMA (vanilylmandelic acid) test for catechols. It may also falsely elevate the level of urinary 5-HIAA (5-hydroxyindoleacetic acid) in certain serotonin metabolite chemical tests because of color interference.

Drug Interactions: Serious toxicity may result if dextromethorphan is coadministered with monoamine oxidase inhibitors (MAOIs). The use of dextromethorphan hydrobromide may result in additive CNS depressant effects when coadministered with alcohol, antihistamines, psychotropics or other drugs, which produce CNS depression.

Information for Patients: Patients should be warned not to use this product if they are now taking a prescription monoamine oxidase inhibitor (MAOI) (certain drugs for depression, psychiatric or emotional conditions, or Parkinson’s disease), or for 2 weeks after stopping the MAOI drug. If patients are uncertain whether a prescription drug contains an MAOI, they should be instructed to consult a health professional before taking such a product.

Adverse Reactions/Side Effects

Guaifenesin is well tolerated and has a wide margin of safety. Nausea and vomiting are the side effects that occur most commonly. Other reported adverse reactions have included dizziness, headache and rash (including urticaria). Rare drowsiness or mild gastrointestinal disturbances are the only side effects associated with extromethorphan in clinical use. (see also Drug Interactions)


Overdosage with guaifenesin is unlikely to produce toxic effects since its toxicity is low. Guaifenesin, when administered by stomach tube to test animals in doses up to 5 grams/kg, produced no signs of toxicity. In severe cases of overdosage, treatment should be aimed at reducing further absorption of the drug. Gastric emptying (emesis and/or gastric lavage) is recommended as soon as possible after ingestion.

Overdosage with dextromethorphan may produce excitement and mental confusion. Very high doses may produce respiratory depression. One case of toxic psychosis (hyper-activity, marked visual and auditory hallucinations) after ingestion of a single 300 mg dose of dextromethorphan has been reported.

Guaifenesin-DM NR Dosage and Administration

Adults and children 12 years of age and older: 2 teaspoonfuls (10 ML) every four hours not to exceed 12
teaspoonfuls (60 ML) in 24 hours.

Children 6 years to under 12 years of age: 1 teaspoonful (5 ML) every four hours not to exceed 6 teaspoonfuls
(30 ML) in 24 hours.

Children 2 to under 6 years of age: 1/2 teaspoonful (2.5 ML) every four hours not to exceed 3 teaspoonfuls
(15 ML) in 24 hours.

Children under 2 years of age: Consult a physician.

How is Guaifenesin-DM NR supplied

Guaifenesin-DM NR Liquid is available in bottles of 4 oz (118 mL), one pint (473 mL), and one gallon (3785 mL).

Store at controlled room temperature - 15°-30°C (59°-86°F).
Protect from light. Keep bottle tightly closed.

Manufactured by:
Silarx Pharmaceuticals, Inc.
Spring Valley, NY 10977

Container Label

guaifenesin-dm nr liquid liquid
Product Information
Product TypeHUMAN PRESCRIPTION DRUGItem Code (Source)NDC:54838-124
Route of AdministrationORAL
Active Ingredient/Active Moiety
Ingredient NameBasis of StrengthStrength
Guaifenesin (UNII: 495W7451VQ) (Guaifenesin - UNII:495W7451VQ) Guaifenesin100 mg in 5 mL
Dextromethorphan Hydrobromide (UNII: 9D2RTI9KYH) (Dextromethorphan - UNII:7355X3ROTS) Dextromethorphan Hydrobromide10 mg in 5 mL
Inactive Ingredients
Ingredient NameStrength
anhydrous citric acid (UNII: XF417D3PSL)
D&C Yellow No. 10 (UNII: 35SW5USQ3G)
FD&C Red No. 40 (UNII: WZB9127XOA)
glycerin (UNII: PDC6A3C0OX)
methylparaben (UNII: A2I8C7HI9T)
propylene glycol (UNII: 6DC9Q167V3)
saccharin sodium (UNII: SB8ZUX40TY)
sodium benzoate (UNII: OJ245FE5EU)
sorbitol (UNII: 506T60A25R)
water (UNII: 059QF0KO0R)
sodium citrate (UNII: 1Q73Q2JULR)
Product Characteristics
Color Score
FlavorRASPBERRYImprint Code
#Item CodePackage DescriptionMarketing Start DateMarketing End Date
1NDC:54838-124-80473 mL in 1 BOTTLE, PLASTIC
Marketing Information
Marketing CategoryApplication Number or Monograph CitationMarketing Start DateMarketing End Date
unapproved other05/01/2000
Labeler - Silarx Pharmaceuticals, Inc (161630033)