Dosing & Uses
Dosage Forms & Strengths
tablet
- 15mg
capsule
- 15mg
gel, oral
- 7.5mg/5mL
liquid, oral
- 7.5mg/5mL
- 10mg/5mL
- 15mg/5mL
syrup, oral
- 5mg/5mL
- 7.5mg/5mL
- 10mg/5mL
- 15mg/5mL
- 20mg/15mL
liquid, extended release
- 30mg/5mL
lozenge
- 5mg
- 7.5mg
- 15mg
strip, oral
- 7.5mg
Cough
Liquid and syrup: 10-20 mg PO q4hr OR 30 mg q6-8hr
Gel: 30 mg PO q6-8hr; not to exceed 120 mg/24hr
Extended release: 60 mg PO q12hr; not to exceed 120 mg/24hr
Lozenges: 5-15 mg PO q1-4hr; not to exceed 120 mg/day
Strips: 30 mg PO q6-8hr; not to exceed 120 mg/day
Dosing considerations
- Abuse potential much lower than codeine
- About 15-30 mg dextromethorphan equal to 8-15 mg codeine as an antitussive
Dosage Forms & Strengths
tablet
- 15mg
capsule
- 15mg
- 25mg
gel, oral
- 7.5mg/5mL
syrup
- 5mg/5mL
- 7.5mg/5mL
- 10mg/5mL
- 15mg/5mL
- 20mg/15mL
liquid, extended release
- 30mg/5mL
lozenge
- 5mg
- 7.5mg
- 15mg
strip, oral
- 7.5mg
Cough
<4 years
- Prescription only
Extended release
- 4-6 years: 15 mg PO twice daily; not to exceed 30 mg/24hr
- 6-12 years: 30 mg PO twice daily; not to exceed 60 mg/24hr
- >12 years: 60 mg PO q12hr; not to exceed 120 mg/24hr
Liquid/Syrup
- 4-6 years: 7.5 mg q6-8hr (not to exceed 30 mg/day)
- 6-12 years: 15 mg PO q6-8hr; not to exceed 60 mg/24hr
- 12 years: 10-20 mg PO q4hr or 30 mg q6-8hr not to exceed 120 mg/24hr
Gel
- >12 years: 30 mg PO q6-8hr; not to exceed 120 mg/24hr
Lozenges
- 6-12 years: 5-10 mg q1-4hr; not to exceed 60 mg/day
- >12 years: 5-15 mg PO q1-4hr; not to exceed 120 mg/day
Strips
- 6-12 years: 15 mg PO q6-8hr; not to exceed 60 mg/day
- >12 years: 30 mg PO q6-8hr; not to exceed 120 mg/day
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Adverse Effects
Common
Nausea
Vomiting
Constipation
Drowsiness
Dizziness
Sedation
Confusion
Nervousness
Warnings
Contraindications
Concurrent nonselective MAO inhibitors: Serotonin syndrome
Cautions
Phenylketonuria: Contains aspartame
Hallucinations, confusion, agitation, hyper-reflexia, shivering, myoclonus, and tachycardia may occur
Caution in children younger than 6 years
Not for use in children <4 years
Use caution in patients who are sedated, debilitated or confined to supine posiiton
Pregnancy & Lactation
Pregnancy category: C
Lactation: Not known if excreted in breast milk; use caution
Pregnancy Categories
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Pharmacology
Mechanism of Action
Acts on cough center in medulla; decreases sensitivity of cough receptors and interrupts cough impulse transmission
Derivative of levorphanol
Absorption
Onset: 15-30 min
Duration: ≤6 hr
Time to peak: 2-3hr
Metabolism
Hepatic P450 enzyme CYP2D6
Elimination
Half-life: 2-4hr (extensive metabolizers); 24 hr (poor metabolizers)
Excretion: Urine
Pharmacogenomics
CYP2D6 substrate
Approximately 7-10% of Caucasians and 3-8% of African Americans lack the capacity to metabolize CYP2D6 substrates and are classified as poor metabolizers
Genetic testing laboratories
- Genotyping tests for CYP2D6 variants are commercially available through the following companies:
- Applied Biosystems (http://www.appliedbiosystems.com/)
- GenPath Diagnostics (http://www.genpathdiagnostics.com/)
