Dextromethorphan
DELSYM
Pronunciation: dex-troe-meth-OR-fan
“Dexter the Thor fan”
What it isNMDA antagonist and sigma-1 agonist; cough, and with bupropion or quinidine for depression and pseudobulbar affect.
Why this oneIts NMDA action gives rapid antidepressant effect when metabolism is blocked by a partner drug.
What limits itSerotonin syndrome with MAOIs and serotonergic drugs. CYP2D6-dependent, and it is abused at high dose.
FDA-approved for
- cough (~1958)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Cough from minor throat/bronchial irritation (cold, inhaled irritants) | Adults & children ≥12 yr | 10 mL q12h | 10 mL q12h | 20 mL/24 h |
| Cough from minor throat/bronchial irritation (cold, inhaled irritants) | Children 6 to <12 yr | 5 mL q12h | 5 mL q12h | 10 mL/24 h |
| Cough from minor throat/bronchial irritation (cold, inhaled irritants) | Children 4 to <6 yr | 2.5 mL q12h | 2.5 mL q12h | 5 mL/24 h |
Renal Undefined
Hepatic Undefined
Children under 4 yr: do not use.
Instructions
- Shake bottle well before use
- Measure only with the dosing cup provided; do not use the cup with other products
Available strengths
- ER susp 30 mg
- cap 15 mg
- tab 15, 30 mg
- chew tab 10, 15 mg
- lozenge 5, 10 mg
- sol 30 mg/10 mL
- sol 20 mg/20 mL
- sol 5, 7.5, 10, 15 mg/5 mL
- + 2 other marketed forms not shown
Contraindications
- MAOIs (now taking, or within 2 weeks of stopping)
Cautions
- Ask a doctor before use: chronic cough (smoking, asthma, emphysema) or cough with too much phlegm
- Stop use and ask a doctor if cough lasts >7 days, comes back, or occurs with fever, rash, or lasting headache
Pregnancy If pregnant, ask a health professional before use.
Lactation If breast-feeding, ask a health professional before use.
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 30 mg | ER susp | per unit | $0.07/mL | not offered |
Available combined with: dextromethorphan / bupropion · dextromethorphan / quinidine
NO BOXED WARNINGS
Principal riskSerotonin syndrome with MAOIs; abuse at high dose
Classes and tags
Clinical profile
Serotonin and MAOI
Provisional washout figures
Elevating mechanismSRI
Evidence confidenceHigh
InterpretationStrongest of the matched opioid/cough hSERT panel at 0.068 uM, above tramadol. Gillman: has SRI properties, best avoided with MAOIs. OTC.
Active metabolites
Open Dextromethorphan in the interactive console ↗
Memory aids: interaction avatars
