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Guiadrine DX

Generic name: dextromethorphan hydrobromide and guaifenesin
Dosage form: oral liquid
Drug class: Upper respiratory combinations

Medically reviewed by Last updated on Sep 21, 2020.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Alcohol Free • Sugar Free

Guiadrine DX Description

A clear, purple liquid having a grape flavor and odor. Each teaspoonful (5mL) contains:

Dextromethorphan Hydrobromide, USP 25 mg
Guaifenesin, USP 225 mg


Sodium Benzoate, Citric Acid, Saccharin Sodium, Propylene Glycol, Polyethylene Glycol, Sorbitol Solution, Sucralose, Grape Flavor, FD&C Blue No. 1, FD&C Red No. 40 and Purified Water.

Dextromethorphan Hydrobromide is an antitussive with the chemical name 3-Methoxy-17-methyl-9α, 13α, 14α-morphinan hydrobromide monohydrate. Its structure is as follows:

C18H25NO • HBr • H2O M.W. 370.32

Guaifenesin is an expectorant with the chemical name 1,2-Propanediol, 3-(2-methoxyphenoxy)-, (±)-. Its structural formula is as follows:

C10H14O4 M.W. 198.22

Guiadrine DX - Clinical Pharmacology

Dextromethorphan is an antitussive agent which, unlike the isomeric levorphanol, has no analgesic or addictive properties. The drug acts centrally and elevates the threshold for coughing. It is about equal to codeine in depressing the cough reflex. In therapeutic dosage, dextromethorphan does not inhibit ciliary activity. Dextromethorphan is rapidly absorbed from the gastrointestinal tract, metabolized by the liver and excreted primarily in the urine.

Guaifenesin is an expectorant which increases respiratory tract fluid secretions and helps to loosen phlegm and bronchial secretions. By reducing the viscosity of secretions, guaifenesin increases the efficiency of the cough reflex and of ciliary action in removing accumulated secretions from the trachea and bronchi. Guaifenesin is readily absorbed from the gastrointestinal tract and is readily metabolized and excreted in the urine. Guaifenesin has a plasma half-life of one hour. The major urinary metabolite is β-(2-methoxyphenoxy) lactic acid.

Indications and Usage for Guiadrine DX

For the temporary relief of cough due to minor throat and bronchial irritation associated with a cold or inhaled irritants and help loosen phlegm (mucus) and thin bronchial secretions to drain bronchial tubes. This product helps to control the cough reflex that causes coughing.


Guiadrine™ DX is contraindicated in patients with a hypersensitivity to any of its ingredients. Guiadrine™ DX should not be used in patients receiving monoamine oxidase inhibitor therapy (MAOI) and for 14 days after stopping MAOI therapy.


Do not exceed recommended dosage. Do not take this product for persistent or chronic cough such as occurs with smoking, asthma, emphysema, or where excessive secretions accompany cough, except under the advice and supervision of a physician.

A persistent cough may be a sign of a serious condition. If cough persists for more than 1 week, tends to recur, or is accompanied by a fever, rash, or persistent headache, consult a doctor.



Before prescribing medication to suppress or modify cough, it is important that the underlying cause of cough is identified, that modification of cough does not increase the risk of clinical or physiological complications, and that appropriate therapy for the primary disease is instituted.

Dextromethorphan should be used with caution in sedated or debilitated patients, and in patients to be confined to the supine position.

Drug Interactions

Do not use this product if you 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 you are uncertain whether your prescription drug contains an MAOI, consult a health professional before taking this product.

Drug/Laboratory Test Interactions

Guaifenesin may increase renal clearance for the urate and thereby lower serum uric acid levels. Guaifenesin may produce an increase in urinary 5-hydroxyindoleacetic acid and may therefore interfere with the interpretation of this test for the diagnosis of carcinoid syndrome. It may also falsely elevate the VMA test for catechols. Administration of this drug should be discontinued 48 hours prior to the collection of urine specimens for such tests.

Carcinogenesis, Mutagenesis, Impairment of Fertility

No data is available on the long-term potential for carcinogenesis, mutagenesis, or impairment of fertility in animals or humans.


Category C

Animal reproduction studies have not been conducted with this product. It is not known whether this medication can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Therefore, Guiadrine™ DX Liquid should be given to a pregnant woman only if the potential benefit justifies the possible risk to the fetus.

Nursing Mothers

It is not known whether Guiadrine™ DX Liquid is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when this drug is 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.

Pediatric Use

Safety and effectiveness in the pediatric population, under 12, have not been established.

Adverse Reactions

Dextromethorphan Hydrobromide: occasionally causes slight drowsiness, dizziness, and gastrointestinal disturbances.

Guaifenesin: Nausea and vomiting are the most frequently occurring side effects.


Overdosage with dextromethorphan may produce central excitement and mental confusion. Very high doses may produce respiratory depression.

Overdosage with guaifenesin is unlikely to produce toxic effects since its toxicity is low.


In severe cases of overdosage, treatment should be aimed at reducing further absorption of the drug. Gastric emptying (Syrup of Ipecac) and/or lavage is recommended as soon as possible after ingestion.

Guiadrine DX Dosage and Administration

Adults and Children 12 years of age or older

1 teaspoonful (5 mL) every 4 hours, not to exceed 6 teaspoonfuls in 24 hours.

This product is not indicated for use in children under 12 years of age. (see PRECAUTIONS, Pediatric Use.)

How Supplied

Guiadrine™ DX Liquid is a sugar free, alcohol free grape flavored, clear, purple liquid. Supplied in 16 fl. oz. (473 mL) bottles, NDC 51991-633-16.

Dispense in a tight, light-resistant container with a child-resistant closure as defined in the USP/NF.

Store at 25°C (77°F); excursions permitted to 15°-30° C (59°-86°F). See USP Controlled Room Temperature. Protect from freezing.

Keep this and all medications out of the reach of children. In case of accidental overdose, seek professional assistance or contact a Poison Control Center immediately.

All prescription substitutions using this product shall be pursuant to state statutes as applicable. This is not an Orange Book product.

Rx Only

Manufactured by:
Tri-Med Laboratories, Inc.,
Somerset, NJ 08873

Distributed by:
Breckenridge Pharmaceutical, Inc.,
Boca Raton, FL 33487

Iss. 1/09


Pharmaceutical, Inc.

NDC 51991-633-16

Guiadrine™ DX

  • Sugar Free
  • Alcohol Free

Description: Each 5mL (one teaspoonful) for oral
administration contains:

Dextromethorphan Hydrobromide, USP 25 mg
Guaifenesin, USP 225 mg

Do not use if inner seal is broken or missing.

Rx Only

Net Contents:
16 fl. oz. (One Pint) 473 mL

Guiadrine DX
dextromethorphan hydrobromide and guaifenesin liquid
Product Information
Product Type HUMAN PRESCRIPTION DRUG LABEL Item Code (Source) NDC:51991-633
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Dextromethorphan Hydrobromide (Dextromethorphan) Dextromethorphan Hydrobromide 25 mg in 5 mL
Guaifenesin (Guaifenesin) Guaifenesin 225 mg in 5 mL
Inactive Ingredients
Ingredient Name Strength
Sodium Benzoate
Citric Acid Monohydrate
saccharin sodium
Propylene Glycol
Polyethylene Glycol
FD&C Blue No. 1
FD&C Red No. 40
Product Characteristics
Color PURPLE (clear) Score
Shape Size
Flavor GRAPE Imprint Code
# Item Code Package Description
1 NDC:51991-633-16 473 mL in 1 BOTTLE, PLASTIC
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
UNAPPROVED DRUG OTHER 11/20/2009 10/31/2011
Labeler - Breckenridge Pharmaceutical, Inc. (150554335)
Name Address ID/FEI Operations
Trimed 182050567 MANUFACTURE
Breckenridge Pharmaceutical, Inc.

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