Note: This document contains side effect information about dextromethorphan / doxylamine. Some dosage forms listed on this page may not apply to the brand name Vicks Nyquil Cough.
Applies to dextromethorphan / doxylamine: oral liquid.
Do not use this medicine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.
You should not use antihistamine medication to make a child sleepy.
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 dextromethorphan and doxylamine and call your doctor at once if you have:
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severe dizziness or anxiety;
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a light-headed feeling, like you might pass out;
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little or no urinating; or
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liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Common side effects may include:
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drowsiness, dizziness;
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nervousness;
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sleep problems (insomnia); 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.
