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Compare Mucinex vs. Dayquil

Head-to-head comparisons of medication uses, side effects, warnings, and more.

Key takeaways

Guaifenesin ER (Mucinex ER, Mucus Relief ER) and acetaminophen/dextromethorphan/phenylephrine (Vicks Dayquil Cold and Flu Multi-Symptom Relief, Theraflu Severe Cold and Cough) are both over-the-counter medications used to treat symptoms related to respiratory conditions. Guaifenesin ER is an expectorant that helps loosen mucus in the chest, making it easier to cough up, while Dayquil Cold and Flu is a combination medication that includes an analgesic, a cough suppressant, and a decongestant to relieve multiple cold and flu symptoms. Guaifenesin ER is taken every 12 hours and is available in extended-release tablets, whereas Dayquil Cold and Flu is typically taken every 4 hours and comes in both pill and liquid forms. Guaifenesin ER is generally well-tolerated with few side effects, but may cause nausea and dizziness, while Dayquil Cold and Flu can cause stomach upset and nervousness, and has more serious risks like liver damage if taken in excess. Additionally, Dayquil Cold and Flu should not be taken with alcohol or certain medications like MAOIs due to potential interactions, whereas guaifenesin ER has no known interactions with alcohol but should be used cautiously with other similar medications to avoid overdose.

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