Classes
DEA Class; OTC
Common Brand Names; Vicks NyQuil Cough, Safetussin PM
- Antitussives, Non-narcotic Combos
Description
Doxylamine: Competitively blocks histamine from binding to H1 receptors; significant antimuscarinic activity & penetrates CNS, which causes pronounced tendency to induce sedation
Dextromethorphan: Cough suppressant that acts centrally on the cough center in medulla
Indications
Contraindications
Hypersensitivity
Asthma attacks
Use of MAO inhibitors within 14 days
< 2 years of age
Narrow-angle glaucoma
Breastfeeding
Symptomatic prostate hypertrophy
Bladder-neck obstruction
Stenosing peptic ulcer
Adverse Effects
Common Adverse Effects
- Agranulocytosis
- Potential for abuse
- Leukopenia
- Serotonin syndrome
- Dizziness
- Drowsiness
- Thrombocytopenia
- Toxic psychosis
- GI disturbances
- Dry mouth, throat, and nose
- Thickening of mucus in nose or throat
- Constipation
- Blurred vision
- Headache
- Urinary retention
Warnings
Caution in patients < 6 years of age
Doxylamine: Caution in used concomitantly with another CNS deppressatn; may exacerbate angle closure glaucoma, hyperthyroidism, peptic ulcer, or urinary tract obstruction; xerostomia may occur; caution in COPD, cardiovascular disease, asthma, increased intraocular pressure, elderly patients or GI obstruction
Dextromethorphan: Do not take for persistent or chronic cough associated with smoking, asthma, or emphysema, or if it is accompanied by excessive phlegm unless directed by a healthcare provider; may decrease respiration rate
Pregnancy and Lactation
Pregnancy category: C
Lactation: excreted in breast milk, use caution
Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs
Maximum Dosage
30 mL PO q6hr; not to exceed 4 doses/day
How supplied
Doxylamine/dextromethorphan
oral liquid
- (6.25mg/15mg)/15mL
