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Acetaminophen, Guaifenesin, and Phenylephrine Liquid

Generic Name: Acetaminophen, Guaifenesin, and Phenylephrine Liquid (a seet a MIN oh fen, gwye FEN e sin, & fen il EF rin)
Brand Name: Theraflu Warming Relief Cold & Chest Congestion

Medically reviewed by Drugs.com. Last updated on Feb 16, 2019.

Uses of Acetaminophen, Guaifenesin, and Phenylephrine Liquid:

  • It is used to treat nose stuffiness.
  • It is used to thin mucus so it can be taken from the body by coughing.
  • It is used to ease pain and fever.

What do I need to tell my doctor BEFORE I take Acetaminophen, Guaifenesin, and Phenylephrine Liquid?

This is not a list of all drugs or health problems that interact with acetaminophen, guaifenesin, and phenylephrine liquid.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take acetaminophen, guaifenesin, and phenylephrine liquid with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Acetaminophen, Guaifenesin, and Phenylephrine Liquid?

  • Tell all of your health care providers that you take acetaminophen, guaifenesin, and phenylephrine liquid. This includes your doctors, nurses, pharmacists, and dentists.
  • Do not take more than what your doctor told you to take. Taking more than you are told may raise your chance of very bad side effects.
  • Do not take acetaminophen, guaifenesin, and phenylephrine liquid for longer than you were told by your doctor.
  • Avoid taking other products that have acetaminophen in them. Check labels closely. Too much acetaminophen may cause liver problems.
  • This medicine has acetaminophen in it. Liver problems have happened with the use of acetaminophen. Sometimes, this has led to a liver transplant or death. Most of the time, liver problems happened in people taking more than 4,000 mg (milligrams) of acetaminophen in a day. People were also often taking more than 1 drug that had acetaminophen in it. If you have questions, talk with your doctor.
  • Follow the directions exactly. Do not take more acetaminophen in a day than directed. If you do not know how much acetaminophen you can take in a day, ask your doctor or pharmacist. Some people may take up to 4,000 mg (milligrams) in a day if told to do so by the doctor. Some people (like people with liver problems and children) should take less acetaminophen. Call your doctor right away if you have taken too much acetaminophen in a day, even if you feel well.
  • Talk with your doctor before you drink alcohol.
  • This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take acetaminophen, guaifenesin, and phenylephrine liquid.
  • This medicine may not be for use in children of all ages. Talk with the doctor before giving acetaminophen, guaifenesin, and phenylephrine liquid to a child.
  • Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is this medicine (Acetaminophen, Guaifenesin, and Phenylephrine Liquid) best taken?

Use acetaminophen, guaifenesin, and phenylephrine liquid as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Take with or without food. Take with food if it causes an upset stomach.
  • Drink lots of noncaffeine liquids every day unless told to drink less liquid by your doctor.
  • Measure liquid doses carefully. Use the measuring device that comes with acetaminophen, guaifenesin, and phenylephrine liquid. If there is none, ask the pharmacist for a device to measure acetaminophen, guaifenesin, and phenylephrine liquid.

What do I do if I miss a dose?

  • If you take acetaminophen, guaifenesin, and phenylephrine liquid on a regular basis, take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.
  • Many times acetaminophen, guaifenesin, and phenylephrine liquid is taken on an as needed basis. Do not take more often than told by the doctor.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
  • Not able to pass urine or change in how much urine is passed.
  • A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.

What are some other side effects of Acetaminophen, Guaifenesin, and Phenylephrine Liquid?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Dizziness.
  • Feeling nervous and excitable.
  • Trouble sleeping.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Acetaminophen, Guaifenesin, and Phenylephrine Liquid?

  • Store at room temperature. Do not refrigerate or freeze.
  • Store in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer information use

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
  • Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about acetaminophen, guaifenesin, and phenylephrine liquid, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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