Dextromethorphan Hydrobromide; Guaifenesin
Indications: Cough
DESCRIPTION:
Each dye-free, scored, long-acting tablet for oral administration contains:
Dextromethorphan HBr
30 mg
Guaifenesin
500 mg
In a special base to provide a prolonged therapeutic effect. This product contains ingredients of the following therapeutic classes: antitussive and expectorant. Also contains maltodextrin, stearic acid, collodial silicon dioxide, povidone, methylcellulose, and magnesium stearate.
Guaifenesin is an expectorant having the chemical name 1,2-Propanediol,3-(2-methoxyphenoxy)-,(Β±)- and has the following chemical formula: C10H14O4. Its molecular weight is 198.22
Dextromethorphan hydrobromide is an antitussive having the chemical name, 3-methoxy-17-methyl-9alpha,13alpha, 14alpha-morphinan hydrobromide monohydrate and has the following chemical formula: C18H25NOΒ·HBrΒ·H2O. Its molecular weight is 370.33.
CLINICAL PHARMACOLOGY:
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 rapidly metabolized and excreted in the urine. Guaifenesin has a plasma half-life of one hour. The major urinary metabolite is beta-(2-methoxyphenoxy) lactic acid.
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.
INDICATIONS AND USAGE:
Dextromethorphan hydrobromide; guaifenesin tablets are indicated for the temporary relief of coughs associated with upper respiratory tract infections and related conditions such as sinusitis, pharyngitis, and bronchitis, particularly when these conditions are complicated by tenacious mucus and/or mucus plugs and congestion. Dextromethorphan hydrobromide; guaifenesin tablets are effective in productive as well as non-productive cough, but are of particular value in dry, non-productive cough which tends to injure the mucous membrane of the air passages.
CONTRAINDICATIONS:
Dextromethorphan hydrobromide; guaifenesin tablets are contraindicated in patients with hypersensitivity to guaifenesin or dextromethorphan. Dextromethorphan hydrobromide; guaifenesin tablets should not be used in patients receiving monoamine oxidase inhibitor (MAOI) therapy and for 14 days after stopping MAOI therapy.
PRECAUTIONS:
General: 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/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, and Impairment of Fertility: No data are available on the long-term potential for carcinogenesis, mutagenesis, or impairment of fertility in animals or humans.
Pregnancy Category C: Animal reproduction studies have not been conducted with guaifenesin or with dextromethorphan. It is also not known whether these drugs can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. This product should be given to a pregnant woman only if clearly needed.
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 drugs are administered to a nursing woman and a decision should be made whether to discontinue nursing or to discontinue the drugs, taking into account the importance of the drugs to the mother.
ADVERSE REACTIONS:
No serious side effects from guaifenesin or dextromethorphan have been reported.
OVERDOSAGE:
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 (Syrup of Ipecac) and/or lavage is recommended as soon as possible after ingestion.
Overdosage with dextromethorphan may produce central excitement and mental confusion. Very high doses may produce respiratory depression. One case of toxic psychosis (hyperactivity, marked visual and auditory hallucinations) after ingestion of a single 300 mg dose of dextromethorphan has been reported.
DOSAGE AND ADMINISTRATION:
Adults and Children Over 12 Years of Age: 1 or 2 tablets every 12 hours not to exceed 4 tablets in 24 hours.
Children 6 to 12 Years of Age: 1 tablet every 12 hours not to exceed 2 tablets in 24 hours.
Children 2 to 6 Years of Age: 1/2 tablet every 12 hours not to exceed 1 tablet in 24 hours.