Dextromethorphan

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Dextromethorphan (brand name Delsym) — Antitussive; Central cough suppressant.

Identification

• Therapeutic class: Antitussive.
• Pharmacologic class: Central cough suppressant.

Pharmacology

• Mechanism of action: Acts centrally to raise the cough threshold.
• Onset / peak / duration: Onset 15 to 30 minutes; ER lasts about 12 hours.
• Half-life / therapeutic level: Variable; no routine level.

Clinical use

• Indications: Nonproductive cough.
• Usual dose, route, frequency: 10 to 30 mg PO every 4 to 8 hours, or ER twice daily.
• Maximum dose / adjustments: Max about 120 mg/day.

Safety

• Contraindications: Use with MAO inhibitors (serotonin syndrome risk).
• Black box warning: None.
• Interactions: MAO inhibitors and serotonergic drugs (serotonin syndrome), alcohol (additive sedation, food/drink).
• Pregnancy / lactation: Use if needed.
• High-alert: No.

Adverse effects

• Common side effects: Drowsiness, dizziness, nausea.
• Serious effects to report: Serotonin syndrome, signs of misuse.
• Antidote / reversal: Supportive care.

Nursing process

• Assessment before administration: Cough type, other serotonergic drugs.
• Interventions during therapy: Avoid combining with MAO inhibitors.
• Monitor: Cough relief, sedation.
• Evaluation / expected outcome: Reduced cough.

Patient teaching

• Patient teaching: Avoid alcohol; do not exceed the dose.
• Notify provider if: Agitation, fever, rapid heartbeat (serotonin syndrome).
• Administration tips: Shake liquid; do not combine with MAO inhibitors.