Alka-Seltzer Plus Severe Sinus Congestion & Cough (Night Formula) Side Effects

Generic name: acetaminophen / dextromethorphan / doxylamine / phenylephrine

Medically reviewed by Drugs.com. Last updated on Jun 12, 2022.

Note: This document contains side effect information about acetaminophen / dextromethorphan / doxylamine / phenylephrine. Some dosage forms listed on this page may not apply to the brand name Alka-Seltzer Plus Severe Sinus Congestion & Cough (Night Formula).

Applies to acetaminophen / dextromethorphan / doxylamine / phenylephrine: oral capsule, oral liquid, oral tablet, oral tablet effervescent.

Warning

Do not use this medicine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, and tranylcypromine.

Do not take more of this medication than is recommended. An overdose of acetaminophen can damage your liver or cause death. Call your doctor at once if you have nausea, pain in your upper stomach, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of your skin or eyes).

In rare cases, acetaminophen may cause a severe skin reaction. Stop taking this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

In rare cases, acetaminophen may cause a severe skin reaction that can be fatal. This could occur even if you have taken acetaminophen in the past and had no reaction. Stop taking this medicine and call your doctor right away if you have skin redness or a rash that spreads and causes blistering and peeling. If you have this type of reaction, you should never again take any medicine that contains acetaminophen.

Stop using this medicine and call your doctor at once if you have:

pounding heartbeats or fluttering in your chest;
a light-headed feeling, like you might pass out;
anxiety, hallucinations, feeling of fear;
little or no urinating;
pale skin, unusual weakness;
nausea, pain in your upper stomach, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of your skin or eyes); or
dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, chest pain, shortness of breath, uneven heartbeats, seizure).

Common side effects may include:

drowsiness;
constipation, diarrhea, upset stomach, vomiting; or
feeling restless or excited.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to acetaminophen/dextromethorphan/doxylamine/phenylephrine: oral capsule, oral liquid, oral powder for reconstitution, oral tablet, oral tablet effervescent.