Avoid Dextromethorphan-Containing Cough Medications While Taking Lexapro
You should avoid cough suppressants containing dextromethorphan (such as Robitussin DM, Delsym, NyQuil Cough) while taking escitalopram (Lexapro) due to the risk of serotonin syndrome, a potentially life-threatening drug interaction. 1
The Drug Interaction Risk
- Dextromethorphan combined with SSRIs like escitalopram can cause serotonin syndrome, even when dextromethorphan is taken at supratherapeutic doses with therapeutic SSRI levels 1
- In documented cases, patients on escitalopram who took excessive dextromethorphan developed confirmed serotonin syndrome with serum dextromethorphan levels of 950 ng/mL (normal <5) alongside therapeutic escitalopram levels of 23 ng/mL 1
- Serotonin syndrome presents with muscle rigidity, hyperthermia, altered mental status, mydriasis (dilated pupils), flushed skin, and potentially life-threatening complications including convulsions 2
- This interaction can require intensive care unit admission, intubation, and aggressive treatment with benzodiazepines and serotonin antagonists 2
Safe Alternative Cough Treatments
First-Line Non-Pharmacological Options
- Honey and lemon mixture is the recommended first-line treatment, offering patient-reported benefit without drug interaction risk 3, 4
- Voluntary cough suppression through conscious effort can reduce cough frequency through central modulation 3
Safe Pharmacological Alternatives
- First-generation sedating antihistamines (such as diphenhydramine) can suppress cough and are particularly useful for nighttime cough, though they cause drowsiness 3, 5
- Menthol inhalation (menthol crystals or proprietary capsules) provides acute but short-lived cough suppression without serotonin interaction 3, 4
- Inhaled ipratropium is effective for postinfectious cough and does not interact with SSRIs 3
Critical Clinical Pitfall
- Over-the-counter cough medications frequently contain dextromethorphan as the active antitussive ingredient, and patients may not recognize the risk when self-medicating 6
- Always check the active ingredients list on any cough medication before use while taking escitalopram 3
- Even "therapeutic" or recommended doses of dextromethorphan may pose risk when combined with SSRIs, though most documented cases involve supratherapeutic dextromethorphan doses 1
When to Seek Emergency Care
- If you accidentally take dextromethorphan while on escitalopram and develop muscle rigidity, confusion, fever, dilated pupils, or flushed skin, seek immediate emergency medical attention 2, 1
- Serotonin syndrome can progress rapidly and requires urgent treatment 2