Can NyQuil (acetaminophen, dextromethorphan, and doxylamine) be taken with Sudafed (pseudoephedrine)?

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Last updated: May 7, 2025View editorial policy

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From the Guidelines

It is not recommended to take NyQuil and Sudafed together without consulting a healthcare provider first. These medications contain different active ingredients that may overlap or interact. NyQuil typically contains acetaminophen, dextromethorphan, and an antihistamine, while Sudafed contains pseudoephedrine or phenylephrine, which are a-adrenergic agonists that can reduce nasal congestion 1. Taking both could lead to excessive decongestant effects, increased blood pressure, or potential overstimulation of the central nervous system.

Some key considerations when taking these medications together include:

  • Excessive decongestant effects
  • Increased blood pressure
  • Potential overstimulation of the central nervous system
  • Inadvertent double-dosing on certain ingredients
  • Increased risk of side effects like dizziness, nervousness, insomnia, or increased heart rate

If you're experiencing multiple cold or flu symptoms, it's better to choose a single product that targets your specific symptoms or consult with a pharmacist or doctor for guidance on which medications can be safely taken together. They can recommend appropriate timing or alternative options based on your specific health conditions and other medications you may be taking.

From the Research

Interaction between NyQuil and Sudafed

  • NyQuil and Sudafed are both over-the-counter (OTC) medications used to relieve cold and flu symptoms.
  • NyQuil typically contains active ingredients such as dextromethorphan, doxylamine, and acetaminophen, while Sudafed contains pseudoephedrine or phenylephrine 2.
  • According to a study published in 2020, combinations of 2,3, or 4 active ingredients, including those found in NyQuil and Sudafed, occur frequently in OTC sinonasal products 2.
  • Another study from 2019 developed a method for simultaneous determination of active ingredients in cold and cough medicines, including those found in NyQuil and Sudafed, using reverse phase high performance liquid chromatography (RP-HPLC) 3.
  • A 2007 study also developed a method for separating and determining active components in medicinal preparations, including pseudoephedrine and dextromethorphan, using flow injection-capillary electrophoresis 4.

Potential Interactions

  • Taking NyQuil with Sudafed may increase the risk of adverse effects due to the combination of active ingredients.
  • The specific interaction between NyQuil and Sudafed is not explicitly stated in the provided studies, but the combination of active ingredients may increase the risk of side effects such as drowsiness, dry mouth, and increased heart rate 2, 3, 4.
  • It is essential to follow the recommended dosage and consult a healthcare professional before taking any medication, especially when combining multiple OTC products.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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