Note: This document contains side effect information about chlorpheniramine / dextromethorphan / phenylephrine. Some dosage forms listed on this page may not apply to the brand name Robitussin Cough & Allergy.

Applies to chlorpheniramine / dextromethorphan / phenylephrine: oral liquid, oral solution, oral syrup.

Serious side effects

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Other side effects

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Dizziness.
• Feeling nervous and excitable.
• Not able to sleep.
• Feeling sleepy.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

For Healthcare Professionals

Applies to chlorpheniramine/dextromethorphan/phenylephrine: oral drops, oral liquid, oral syrup, oral tablet, oral tablet effervescent, oral tablet extended release.

Gastrointestinal

Gastrointestinal side effects have included vomiting, diarrhea, dry mouth, nausea, anorexia, heartburn, and GI disturbance.^[Ref]

Nervous system

Nervous system side effects have included sedation, drowsiness, dizziness, nervousness, headache, convulsions, central nervous system stimulation, hallucinations, tremors, and insomnia.^[Ref]

Cardiovascular

Cardiovascular side effects have included cardiac arrhythmias, increased heart rate, and increased blood pressure.^[Ref]

General

General side effects have included weakness and pallor.^[Ref]

Genitourinary

Genitourinary side effects have included polyuria and dysuria. Urinary retention may occur in patients with prostatic hypertrophy.^[Ref]

Respiratory

Respiratory side effects have included respiratory difficulties.^[Ref]

Ocular

Ocular side effects have included diplopia.^[Ref]