What does DayQuil syrup do?

Quick Answers

DayQuil syrup is an over-the-counter medication used to provide temporary relief of common cold and flu symptoms such as cough, sore throat, headache, minor aches and pains, fever, and nasal congestion. It contains the active ingredients acetaminophen, dextromethorphan, and phenylephrine.

How does DayQuil work?

The combination of active ingredients in DayQuil work together to target multiple cold and flu symptoms:

– Acetaminophen is a pain reliever and fever reducer. It helps reduce aches, pains, headache, and fever.

– Dextromethorphan is a cough suppressant. It works by suppressing the cough reflex in the brain.

– Phenylephrine is a decongestant. It constricts blood vessels in the nasal passages, reducing nasal congestion and sinus pressure.

What are the uses and benefits of DayQuil?

DayQuil is intended to be used for temporary relief of the following cold and flu symptoms:

– Coughing
– Sore throat
– Congestion
– Runny nose
– Sneezing
– Headache
– Minor aches and pains
– Fever

The combination of acetaminophen, dextromethorphan, and phenylephrine in DayQuil provides multi-symptom relief by targeting pain, cough, and congestion. This can provide on-the-go relief when you need to power through your day with a cold.

How long does DayQuil last?

The effects of DayQuil typically last for 4 to 6 hours. The acetaminophen component provides fever reduction and pain relief for 4-6 hours. The dextromethorphan cough suppressant effects last for 5-6 hours. Phenylephrine decongestion effects tend to last for 4 hours.

You can take DayQuil every 4 to 6 hours as needed. Do not exceed 4 doses in 24 hours. Make sure to read and follow the dosage directions on the package.

Active Ingredients in DayQuil

DayQuil contains a combination of the following active ingredients:


– Pain reliever and fever reducer
– Reduces headache, minor aches and pains, fever
– Adult dose of 325 mg in each 30 mL of DayQuil

Dextromethorphan HBr

– Cough suppressant
– Suppresses the urge to cough by acting on the cough center in the brain
– Adult dose of 10 mg in each 30 mL of DayQuil

Phenylephrine HCl

– Nasal decongestant
– Constricts blood vessels in nasal passages and sinuses, relieving congestion
– Adult dose of 5 mg in each 30 mL of DayQuil

The combination of these three active ingredients provides relief for the multiple symptoms associated with colds and flu.

DayQuil Formulations and Flavors

DayQuil comes in liquid and caplet formulations. Popular flavors of the DayQuil liquid include:

– Cherry flavored DayQuil
– Green Apple flavored DayQuil
– Grape flavored DayQuil

The caplets are small capsules that can be swallowed easily with water. They provide the same combination of active ingredients as the liquid but do not contain any added flavors.

Both the liquid and caplets should be taken with a full glass of water. Do not exceed 4 doses in 24 hours.

DayQuil LiquiCaps

DayQuil LiquiCaps provide the same powerful cold and flu relief as the syrup, but in easy to take soft gel capsules. The LiquiCaps contain the same combination of acetaminophen, dextromethorphan, and phenylephrine as the syrup.

DayQuil Severe Caplets

DayQuil Severe caplets contain the same ingredients as regular DayQuil caplets, but with a higher dose of dextromethorphan (20 mg vs 10 mg). The higher dose provides more powerful and longer lasting cough suppression for severe coughs.

DayQuil Dosage and Usage

It is important to follow the proper dosage directions when taking DayQuil:

DayQuil Liquid Dosage

Adults and children 12 years and over: Take 30 mL every 4 to 6 hours. Do not exceed 4 doses in 24 hours.

Children under 12 years: Do not use. Consult a doctor.

DayQuil Caplets/LiquiCaps Dosage

Adults and children 12 years and over:

– Regular strength: Take 2 caplets/LiquiCaps with water every 4 to 6 hours.
– Severe strength: Take 2 Severe strength caplets every 12 hours.

Do not exceed 4 doses in 24 hours.

Children under 12 years: Do not use. Consult a doctor.

Other important dosage guidelines:

– Measure liquid DayQuil carefully using dosage cup.
– Take with a full glass of water.
– Do not take more than directed.

How long does it take for DayQuil to work?

DayQuil starts working within 30 minutes to 1 hour after taking a dose. You can expect:

– Cough relief within 30-60 minutes
– Decongestion relief within 1 hour
– Pain/fever reduction within 1 hour
– Peak relief within 2 to 4 hours

Effects last for 4 to 6 hours. Retake dose every 4 to 6 hours as needed.

How long should you take DayQuil?

DayQuil can be used for the duration of cold and flu symptoms or as directed by a doctor. Do not exceed 4 doses per 24-hour period.

It is recommended to take DayQuil for:

– Adults: Up to 5 days
– Children under 12: Up to 3 days

If symptoms persist or worsen after using DayQuil for the recommended time period, contact your doctor. Do not take DayQuil for more than 7 days unless directed by a doctor.

DayQuil Precautions and Warnings

DayQuil is generally safe when used as directed, but there are some important precautions and warnings to be aware of:

Do not exceed recommended dosage

Taking more than the recommended amount of DayQuil can lead to overdose and serious health risks. Never take more than 4 doses per 24-hour period.

Avoid alcohol use

Avoid drinking alcohol while taking DayQuil. Alcohol can intensify the side effects and increase risk of overdose.

Do not use if you are sensitive to ingredients

Do not use DayQuil if you have known hypersensitivity or allergy to acetaminophen, dextromethorphan, phenylephrine or any inactive ingredients in the product. Discontinue use if skin rash or other hypersensitivity reaction develops.

Avoid use in children under 12 years

DayQuil should not be used in children under 12 years of age. Use child formulations appropriate for age and weight in children under 12.

Be cautious with existing medical conditions

Use caution if you have heart, liver, kidney disease, diabetes, glaucoma, cough with excessive phlegm, breathing problems, or difficulty urinating due to prostate enlargement. Consult doctor before use.

Avoid use with other drugs

Avoid taking DayQuil with other drugs and natural products that can increase risk of side effects. Carefully review drug interactions before use.

Stop use if nervousness, dizziness, or sleeplessness occurs

Discontinue use if nervousness, dizziness or sleeplessness occur. These could be signs of phenylephrine overdose.

Not intended for severe coughs or coughs that produce mucus

Do not use DayQuil for chronic coughs or coughs that produce excessive mucus. See a doctor for chronic coughs or evaluation of underlying condition.

Side Effects of DayQuil

When taken as directed, DayQuil is generally well tolerated. However, some possible side effects include:

Common side effects:

– Drowsiness or dizziness
– Nausea, vomiting, stomach upset
– Nervousness or restlessness
– Mild skin rash or redness

Rare but serious side effects:

– Severe allergic reaction (swelling, hives, difficulty breathing)
– Agitation, confusion, hallucinations
– Uncontrollable muscle movements
– Liver damage – symptoms may include nausea, vomiting, stomach pain, fatigue, loss of appetite, dark urine, clay colored stools, jaundice (yellowing of skin or eyes)
– Stevens Johnson syndrome – severe skin reaction with flu-like symptoms and painful red or purplish rash that spreads and blisters

Seek medical help immediately if you experience any serious side effects after taking DayQuil.

DayQuil Drug Interactions

The active ingredients in DayQuil can interact with other medications resulting in increased risk of side effects and complications. Important drug interactions to be aware of include:

Acetaminophen Interactions

– Warfarin – increased risk of bleeding
– Medications broken down by the liver – increased drug levels and side effects
– Carbamazepine – reduced efficacy of carbamazepine

Dextromethorphan Interactions

– MAO inhibitors – dangerous side effects such as high fever, seizures
– Serotonin reuptake inhibitors – risk of serotonin syndrome
– Other cough and cold medications – potential for overdose due to duplicated active ingredients

Phenylephrine Interactions

– Rauwolfia alkaloids – severe high blood pressure
– Stimulants – increased heart rate and blood pressure
– Antidepressants – blood pressure changes

Always check with your doctor or pharmacist about potential interactions before taking DayQuil alongside any other medications, including prescription, OTC, vitamins, and herbal products. Never take more than one cough/cold product at the same time unless directed by a doctor.

Who Should Not Take DayQuil?

DayQuil should be avoided in certain situations. Do not take DayQuil if:

– You are allergic or sensitive to acetaminophen, dextromethorphan, phenylephrine, or inactive ingredients
– You are taking a prescription monoamine oxidase inhibitor (MAOI) such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine
– You are under 12 years old
– You have severe high blood pressure or severe heart conditions
– You have liver disease
– You have glaucoma
– You have trouble urinating due to prostate enlargement
– You are taking tranquilizers or sedatives

Consult your doctor before taking DayQuil if you have any chronic medical conditions, take prescription medications, or are unsure about using the product.

Is DayQuil Safe During Pregnancy and Breastfeeding?

DayQuil has not been studied for safety and efficacy during pregnancy or breastfeeding. Acetaminophen is considered the safest pain reliever for pregnant women when taken as directed. Dextromethorphan and phenylephrine have more limited safety data in pregnancy.

It is best to minimize medications during pregnancy and breastfeeding whenever possible. Small, occasional doses of DayQuil are unlikely to cause harm, but regular use or exceeding the recommended dose is not advised. Consult your obstetrician or midwife before taking DayQuil while pregnant or breastfeeding.

DayQuil and Pregnancy

Here are some key points about DayQuil use during pregnancy:

– Animal studies did not show risk to the fetus, but human studies are lacking.
– Acetaminophen is considered safer than other pain relievers like ibuprofen or aspirin.
– Dextromethorphan and phenylephrine may cause increased heart rate or blood pressure in the mother.
– Avoid use in the first trimester and late pregnancy unless doctor approved.
– Only use temporarily for symptom relief and at the lowest effective dose.

DayQuil and Breastfeeding

Small occasional doses of DayQuil are likely compatible with breastfeeding, but consider these precautions:

– Acetaminophen is considered safe with the lowest effective dose. Avoid chronic high doses.
– Dextromethorphan and phenylephrine pass into breast milk in small amounts. Adverse effects are unlikely at recommended doses.
– Watch for drowsiness, adequate hydration, and proper nutrition in the breastfed infant.
– Monitor infant for any irritability, poor feeding, or rashes after taking DayQuil.
– Consider pumping and discarding milk for 3-8 hours after a dose of DayQuil.

Discuss all medications with your doctor while breastfeeding. Weigh the benefits against the potential risks before taking DayQuil.

Frequently Asked Questions About DayQuil

Can I take DayQuil while taking antibiotics?

Yes, DayQuil can typically be taken safely with most antibiotics. As always check with your doctor about potential interactions. DayQuil helps relieve symptoms while the antibiotic treats the underlying infection. Avoid taking within 2 hours of antibiotics for proper absorption.

Can I take DayQuil on an empty stomach?

It is better to take DayQuil with food or after a meal. Taking on an empty stomach increases risk of stomach upset and nausea from the medication. At minimum take with a full glass of water.

Is DayQuil safe for people with high blood pressure?

Phenylephrine in DayQuil can cause an increase in blood pressure. People with controlled high blood pressure can typically take DayQuil safely, but check with your doctor first. Avoid DayQuil if you have severe uncontrolled hypertension.

Can I drink alcohol while taking DayQuil?

It is best to avoid alcohol while taking DayQuil. Alcohol can amplify the drowsiness caused by DayQuil and increase the risk of liver damage from acetaminophen. Skipping alcohol is advised during use and for several days after stopping DayQuil.

How long does DayQuil stay in your system?

The typical half-life is 1-3 hours for acetaminophen, 3-4 hours for dextromethorphan, and 5-8 hours for phenylephrine. Almost all traces will be eliminated within 24 hours after the last dose.

Can you take NyQuil and DayQuil together?

It is not recommended to take NyQuil and DayQuil together. Both contain acetaminophen and taking doses too close together increases the risk of overdose. Never exceed recommended dosages of acetaminophen from all sources.

Key Takeaways About DayQuil

– DayQuil is an effective OTC medication for relieving multiple symptoms of the common cold and flu including cough, congestion, fever, and body aches.

– The combination of acetaminophen, dextromethorphan, and phenylephrine targets pain, cough, and stuffy nose/sinuses.

– Follow dosage directions carefully and do not take more than directed. Exceeding 4 doses per day can be dangerous.

– Allow at least 4 hours between doses of DayQuil Liquid or LiquiCaps. Wait 12 hours for Severe caplets.

– Avoid alcohol and check for interactions with other medications you take to prevent complications.

– While generally safe for adults, DayQuil should be avoided in children under 12 years old. It is also not recommended during the first and last trimesters of pregnancy.

– Seek medical help if your symptoms worsen or do not improve after taking DayQuil as directed for up to 5 days.

The Bottom Line

DayQuil is an effective and widely used OTC medication that provides temporary relief for multiple cold and flu symptoms. When used correctly and responsibly, it can provide the symptom relief you need to power through your day. However, exceeding dosage recommendations can lead to serious side effects. Use DayQuil cautiously, follow all instructions, and speak to your doctor or pharmacist if you have any concerns before taking it.

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