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Alka-Seltzer Plus Cold and Sinus Side Effects

Generic name: acetaminophen / phenylephrine

Medically reviewed by Last updated on Mar 24, 2024.

Note: This document contains side effect information about acetaminophen / phenylephrine. Some dosage forms listed on this page may not apply to the brand name Alka-Seltzer Plus Cold and Sinus.

Applies to acetaminophen / phenylephrine: oral capsule.

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:

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:

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

For Healthcare Professionals

Applies to acetaminophen/phenylephrine: oral capsule, oral powder for reconstitution, oral tablet, oral tablet chewable, oral tablet effervescent.


Very rare (less than 0.01%): Serious skin reactions

Frequency not reported: Skin rash[Ref]


Frequency not reported: Thrombocytopenia, leukopenia, pancytopenia, neutropenia, agranulocytosis[Ref]

Reports of blood dyscrasias are not necessarily causally related to acetaminophen.[Ref]


Frequency not reported: Abdominal discomfort, nausea, vomiting[Ref]


Frequency not reported: Hypersensitivity[Ref]


Frequency not reported: Urinary retention (especially in males)[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics."

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.