Nyquil and Itching - a phase IV clinical study of FDA data

Summary:

Itching is reported as a side effect among people who take Nyquil (acetaminophen / dextromethorphan / doxylamine / pseudoephedrine), especially for people who are female, 60+ old, have been taking the drug for 2 - 5 years also take Tylenol, and have Primary myelofibrosis.

The phase IV clinical study analyzes which people have Itching when taking Nyquil. It is created by eHealthMe based on reports of 2,013 people who have side effects when taking Nyquil from the FDA, and is updated regularly.

What is Nyquil?

Nyquil has active ingredients of acetaminophen / dextromethorphan / doxylamine / pseudoephedrine. It is often used in cold symptoms. eHealthMe is studying from 2,240 Nyquil users. Check the latest studies of Nyquil.

What is Itching?

Itching is found to be associated with 3,210 drugs and 4,532 conditions by eHealthMe. Check the latest studies of Itching.



On Jul, 08, 2026

2,013 people reported to have side effects when taking Nyquil.
Among them, 48 people (2.38%) have Itching.

Could Nyquil cause Itching?

Among these 48 people:

How long have people been on Nyquil when they have Itching? *

  • < 1 month: 0.0 %
  • 1 - 6 months: 0.0 %
  • 6 - 12 months: 0.0 %
  • 1 - 2 years: 0.0 %
  • 2 - 5 years: 100 %
  • 5 - 10 years: 0.0 %
  • 10+ years: 0.0 %

What is the gender of people who have Itching when taking Nyquil? *

  • female: 66.67 %
  • male: 33.33 %

What is the age of people who have Itching when taking Nyquil? *

  • 0-1: 0.0 %
  • 2-9: 0.0 %
  • 10-19: 0.0 %
  • 20-29: 0.0 %
  • 30-39: 14.81 %
  • 40-49: 25.93 %
  • 50-59: 25.93 %
  • 60+: 33.33 %

What are other drugs people take besides Nyquil? *

  1. Tylenol: 13 people, 27.08%
  2. Vitamin D3: 11 people, 22.92%
  3. Prednisone: 10 people, 20.83%
  4. Benadryl: 7 people, 14.58%
  5. Potassium Chloride: 7 people, 14.58%
  6. Jakafi: 6 people, 12.50%
  7. Proair Hfa: 6 people, 12.50%
  8. Sodium Chloride: 5 people, 10.42%
  9. Escitalopram Oxalate: 5 people, 10.42%
  10. Fish Oil: 5 people, 10.42%

What are other side effects people have besides Itching? *

  1. Fatigue (feeling of tiredness): 24 people, 50.00%
  2. Rashes (redness): 18 people, 37.50%
  3. Nausea (feeling of having an urge to vomit): 14 people, 29.17%
  4. Fever: 13 people, 27.08%
  5. Nasopharyngitis (inflammation of the nasopharynx): 13 people, 27.08%
  6. Malaise (a feeling of general discomfort or uneasiness): 11 people, 22.92%
  7. Thrombocytopenia (decrease of platelets in blood): 11 people, 22.92%
  8. Nausea And Vomiting: 10 people, 20.83%
  9. Splenomegaly (enlargement of spleen): 9 people, 18.75%
  10. Productive Cough: 9 people, 18.75%

What are the existing conditions these people have? *

  1. Primary Myelofibrosis (primary disorder of the bone marrow): 6 people, 12.50%
  2. Asthma: 5 people, 10.42%
  3. High Blood Pressure: 4 people, 8.33%
  4. Soft Tissue Neoplasm (tumour of soft tissue): 4 people, 8.33%
  5. Immunodeficiency: 4 people, 8.33%
  6. Connective Tissue Neoplasm (tumour of connective tissue): 4 people, 8.33%
  7. Hypergammaglobulinaemia (elevated levels of gamma globulin): 3 people, 6.25%
  8. Hypersensitivity: 3 people, 6.25%
  9. Chronic Lymphocytic Leukaemia Refractory (a cancer of blood cells lymphocytes that no longer responds favourably to treatment): 3 people, 6.25%
  10. Stress And Anxiety: 3 people, 6.25%

* Approximation only. Some reports may have incomplete information.

Do you take Nyquil and have Itching?

- Check whether Itching is associated with a drug or a condition
- Predict drug outcomes for up to one year with AI
- Get an AI agent to monitor your drugs continuously



Related studies:

Effectiveness of, long term effects of, and alternative drugs to Nyquil:

Itching treatments and more:

How severe was Itching and when was it recovered:

Expand to all the drugs that have ingredients of acetaminophen / dextromethorphan / doxylamine / pseudoephedrine:

Sub-studies by gender and age:

Female: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Male: 0-1 2-9 10-19 20-29 30-39 40-49 50-59 60+

Browse all side effects of Nyquil:

a b c d e f g h i j k l m n o p q r s t u v w x y z

Browse all the drugs that are associated with Itching:

Browse all the conditions that are associated with Itching:


How the study uses the data?

The study uses data from the FDA. It is based on acetaminophen / dextromethorphan / doxylamine / pseudoephedrine (the active ingredients of Nyquil) and Nyquil (the brand name). Other drugs that have the same active ingredients (e.g. generic drugs) are not considered. Dosage of drugs is not considered in the study.

How to use the study?

DO NOT STOP MEDICATIONS without first consulting your doctor. If there are any serious or long term adverse effects discovered in the study, discuss the study with your doctor to ensure that proper medication management will be in place if applicable.

Who is eHealthMe?

With medical big data and proven AI/ML algorithms, eHealthMe provides a platform for everyone to run phase IV clinical trials. We study millions of patients and 5,000 more each day. Results of our real-world drug study have been referenced on 800+ peer-reviewed medical publications, including The Lancet, Mayo Clinic Proceedings, and Nature. Our analysis results are available to researchers, health care professionals, patients (testimonials), and software developers (open API).

WARNING, DISCLAIMER, USE FOR PUBLICATION

WARNING: Please DO NOT STOP MEDICATIONS without first consulting a physician since doing so could be hazardous to your health.

DISCLAIMER: All material available on eHealthMe.com is for informational purposes only, and is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare provider. All information is observation-only. Our phase IV clinical studies alone cannot establish cause-effect relationship. Different individuals may respond to medication in different ways. Every effort has been made to ensure that all information is accurate, up-to-date, and complete, but no guarantee is made to that effect. The use of the eHealthMe site and its content is at your own risk.

If you use this eHealthMe study on publication, please acknowledge it with a citation: study title, URL, accessed date.



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