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Carbetapentane / diphenhydramine / phenylephrine Side Effects

Applies to carbetapentane/diphenhydramine/phenylephrine: oral suspension extended release, oral tablet chewable extended release, oral tablet extended release.


Use caution when driving, operating machinery, or performing other hazardous activities. Carbetapentane, diphenhydramine, and phenylephrine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while taking carbetapentane, diphenhydramine, and phenylephrine.

Serious side effects are unlikely to occur. Stop taking carbetapentane, diphenhydramine, and phenylephrine and seek emergency medical attention if an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives) is experienced.

Other, less serious side effects may be more likely to occur. Continue to take carbetapentane, diphenhydramine, and phenylephrine and talk to your doctor or try another similar medication if you experience

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

For Healthcare Professionals

Applies to carbetapentane / diphenhydramine / phenylephrine: oral suspension extended release, oral tablet chewable extended release, oral tablet extended release.


Cardiovascular side effects have included hypotension, palpitations, tachycardia, and extrasystoles.[Ref]


Hematologic side effects have included hemolytic anemia, thrombocytopenia, and agranulocytosis.[Ref]

Nervous system

Nervous system side effects have included sedation, sleepiness, dizziness, disturbed coordination, fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesias, vertigo, tinnitus, acute labyrinthitis, headache, neuritis, and convulsions,[Ref]


Ocular side effects have included diplopia and blurred vision.[Ref]


Gastrointestinal side effects have included epigastric distress, anorexia, nausea, vomiting, diarrhea, and constipation.[Ref]


Genitourinary side effects have included urinary frequency, difficult urination, urinary retention, and early menses.[Ref]


Respiratory side effects have included thickening of bronchial secretions, tightness of chest or throat, wheezing, and nasal stuffiness.[Ref]


General side effects have included excessive perspiration, chills, and dryness of mouth, nose and throat.[Ref]


Hypersensitivity side effects have included urticaria, drug rash, anaphylactic shock, and photosensitivity.[Ref]


1. (2003) "Product Information. Dytan CS (carbetapentane / diphenhydramine / phenylephrine)." Hawthorn Pharmaceuticals

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.