Dextromethorphan / Pseudoephedrine / Triprolidine Side Effects
Applies to dextromethorphan / pseudoephedrine / triprolidine: oral liquid.
Important warnings
This medicine can cause some serious health issues
Do not use this medicine if you are using or if you have used an MAO inhibitor in the past 14 days.
A dangerous drug interaction could occur.
MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.
Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.
Stop using this medicine and call your doctor at once if you have:
-
dizziness;
-
nervousness; or
-
sleep problems (insomnia).
Common side effects may include:
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drowsiness; or
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feeling restless or excited (especially in children).
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
See also:
For healthcare professionals
Applies to dextromethorphan/pseudoephedrine/triprolidine: oral liquid.
Cardiovascular adverse events
- Rare (0.01% to 0.1%): Palpitations, hypotension
- Frequency not reported: Dysrhythmias, myocardial infarction/myocardial ischemia, tachycardia, hypertension[Ref]
Dermatologic
- Frequency not reported: Angioedema, pruritus, rash, severe skin reaction, acute generalized exanthematous pustulosis (AGEP), urticaria[Ref]
Gastrointestinal
- Common (1% to 10%): Dry mouth, gastrointestinal disorder, nausea
- Frequency not reported: Abdominal pain, diarrhea, ischemic colitis, vomiting[Ref]
Genitourinary
- Common (1% to 10%): Urinary retention
- Frequency not reported: Dysuria[Ref]
Hematologic
- Rare (0.01% to 0.1%): Blood disorder[Ref]
Hepatic
- Rare (0.01% to 0.1%): Liver disorder[Ref]
Hypersensitivity
- Rare (0.01% to 0.1%): Cross-sensitivity with other sympathomimetics[Ref]
Nervous system
- Very common (10% or more): Headache
- Common (1% to 10%): Dizziness, paradoxical stimulation, psychomotor impairment, somnolence
- Rare (0.01% to 0.1%): Extrapyramidal disorder, seizure, tremor
- Frequency not reported: Cerebrovascular accident, paresthesia, posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome (RCVS), psychomotor hyperactivity[Ref]
Ocular
- Common (1% to 10%): Vision blurred[Ref]
Other
- Frequency not reported: Drug withdrawal syndrome, fatigue[Ref]
Psychiatric
- Common (1% to 10%): Insomnia, nervousness
- Rare (0.01% to 0.1%): Confusion, depression, sleep disorder
- Frequency not reported: Anxiety, drug dependence, euphoric mood, excitability, hallucinations, irritability, paranoid delusions, restlessness[Ref]
Respiratory
- Common (1% to 10%): Increased viscosity of bronchial secretion
- Frequency not reported: Dry throat, epistaxis, nasal dryness, respiratory depression[Ref]
References
1. (2025) "Product Information. Histex-DM New Formulation (Pseudoephedrine) (dextromethorphan / pseudoephedrine / triprolidine)." Allegis Pharmaceuticals
More about dextromethorphan / pseudoephedrine / triprolidine
- Check interactions
- Compare alternatives
- Dosage information
- During pregnancy
- Drug class: upper respiratory combinations
Patient resources
Related treatment guides
Further information
Dextromethorphan/pseudoephedrine/triprolidine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.