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dextromethorphan (Balminil DM, Benylin DM, Bronchophan, Buckleys DM, Calmylin #1, Delsym, Koffex DM, Novahistex DM, Robitussin Lingering Cold Long-Acting Cough, Robitussin Lingering Cold Long-Acting CoughGels, Children's Robitussin Cough Long-Acting, Sucrets 8 Hour Cough Relief DM Cough Formula): Dosing and Uses

 

Classes: Antitussives

Medically reviewed by Min Clinic Staff | Updated: January 2026

Dosing and uses of Balminil DM, Benylin DM (dextromethorphan)

 

Adult dosage forms and 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

 

Pediatric dosage forms and 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

Dosing considerations

  • Potential toxic dose <6 years: 10 mg/kg
  • About 15-30 mg dextromethorphan equal to 8-15 mg codeine as an antitussive

 

Balminil DM, Benylin DM (dextromethorphan) adverse (side) 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 and 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 of Balminil DM, Benylin DM (dextromethorphan)

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 (https://www.appliedbiosystems.com/)
  • GenPath Diagnostics (https://www.genpathdiagnostics.com/)