Medically Reviewed on 7/25/2023

Generic Name: acetaminophen/pheniramine/phenylephrine

Brand Names: Theraflu Cold and Sore Throat, Theraflu Flu and Sore Throat

Drug Class: Antitussives, Non-narcotic Combos

What is acetaminophen/pheniramine/phenylephrine, and what is it used for?

Acetaminophen/pheniramine/phenylephrine is a combination medication used for the temporary relief of common cold and flu symptoms, including runny nose, itchy nose and throat, itchy and watery eyes, fever, headache, minor body aches, cough, sore throat, sneezing and nasal and sinus congestion. The three drugs are combined in specific dosages and the combination is available over the counter (OTC).

Each medication in the combination works in a different way and together they provide more effective relief than any of them as a single agent.

  • Acetaminophen is an analgesic and antipyretic drug used to relieve pain and fever. Acetaminophen relieves pain by blocking pain impulse generation and inhibiting the synthesis of prostaglandin in the central nervous system (CNS). Prostaglandin is a natural substance in the body that initiates inflammation. Acetaminophen reduces fever by acting on the hypothalamus region of the brain which regulates temperature.
  • Pheniramine works by blocking the activity of histamine, a natural compound in the body released by mast cells and basophils, types of immune cells, in response to allergen exposure. Pheniramine binds to histamine H1 receptors in the smooth muscles of blood vessels and the respiratory tract, preventing their activation by histamine that results in allergic reactions such as cough, itching and other symptoms. Pheniramine is a first-generation antihistamine that also causes drowsiness.
  • Phenylephrine is a decongestant drug that belongs to a class of medications known as alpha1 agonists. Phenylephrine stimulates alpha1 adrenergic receptors, protein molecules located in smooth muscle tissues around blood vessels, making these muscles contract. This constricts the blood vessels in the nasal and sinus passages, reducing congestion.


Check with your physician before taking acetaminophen/pheniramine/phenylephrine if you are taking:

Do not take acetaminophen/pheniramine/phenylephrine concurrently with any other drug combination containing acetaminophen. 

Acetaminophen can damage the liver, especially with prolonged use and high doses. Risk factors for severe liver damage include:

  • Taking more than 4,000 mg of acetaminophen in 24 hours
  • Concurrently taking other drugs containing acetaminophen
  • Drinking 3 or more alcoholic drinks while taking acetaminophen

Do not administer to children below 12 years, pheniramine can cause significant excitability and confusion in children.

Use drugs containing phenylephrine with caution in elderly patients.

With acetaminophen use, there have been rare reports of life-threatening skin reactions including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP) with symptoms such as blisters, rash and redness. Discontinue the drug if you develop such symptoms.


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What are the side effects of acetaminophen/pheniramine/phenylephrine?

Common side effects of acetaminophen/pheniramine/phenylephrine include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

  • Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
  • Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
  • Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
  • Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What is the dosage for acetaminophen/pheniramine/phenylephrine?


  • 325 mg/20 mg/10 mg per packet

Allergy Symptoms and Common Cold

Adult and Pediatric:

  • Children below 12 years: Safety and efficacy not established
  • Adults and children 12 years and above: Dissolve contents of 1 packet in 8 oz of hot water; consume entire 8 oz within 10-15 minutes; not to exceed acetaminophen 1 g/dose or 4 g/day


  • Overdose of acetaminophen/pheniramine/phenylephrine can result in severe adverse effects that can be life-threatening or fatal.
  • Acetaminophen overdose can result in liver damage symptoms that include nausea, vomiting, loss of appetite, sweating, abdominal pain, extreme tiredness, yellowing of eyes and skin, dark urine, agitation, confusion, hallucinations and seizures.
  • Pheniramine overdose can cause rapid heart rate (tachycardia), dilated pupils, urinary retention, dry flushed skin, decreased bowel sounds, confusion, mild increase in body temperature, irregular heart rhythms (cardiac arrhythmias), and seizures. In children, overdose may result in excitement first that may be followed by loss of coordination, drowsiness, loss of consciousness and seizures.
  • Phenylephrine overdose can cause headache, vomiting, high blood pressure (hypertension), a reflex drop in the heart rate (bradycardia), a sensation of fullness in the head, tingling of limbs, and irregular heart rhythms (cardiac arrhythmias).
  • Overdose treatment may include administration of N-acetylcysteine, antidote to acetaminophen, and other symptomatic and supportive measures, including gastric lavage and activated charcoal to eliminate the undigested drug.


What drugs interact with acetaminophen/pheniramine/phenylephrine?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe interactions of acetaminophen/pheniramine/phenylephrine include:
    • iobenguane I 123
    • isocarboxazid
    • linezolid
    • phenelzine
    • procarbazine
    • selegiline transdermal
    • tranylcypromine
  • Acetaminophen/pheniramine/phenylephrine has serious interactions with at least 33 different drugs.
  • Acetaminophen/pheniramine/phenylephrine has moderate interactions with at least 188 different drugs.
  • Acetaminophen/pheniramine/phenylephrine has mild interactions with at least 58 different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

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Pregnancy and breastfeeding

  • Acetaminophen/pheniramine/phenylephrine should be used by pregnant women only if clearly needed and potential benefits justify potential risks to the fetus. Use the lowest effective dose for the shortest possible time.
  • Acetaminophen/pheniramine/phenylephrine is present in breastmilk. Use with caution and check with your physician before use if you are breastfeeding.
  • If you are pregnant or breastfeeding, do not take any OTC drug, including acetaminophen/pheniramine/phenylephrine, without first checking with your healthcare provider.

What else should I know about acetaminophen/pheniramine/phenylephrine?

  • Take acetaminophen/pheniramine/phenylephrine exactly as prescribed or as per label instructions if taking OTC medication.
  • Do not take higher or more frequent doses, do not exceed the daily recommended dosage and do not take for prolonged periods.
  • Avoid overdose by checking product labels carefully. Acetaminophen is found in many dosage forms and many combination products. Cumulative doses can be toxic.
  • Discontinue the drug immediately if you develop hypersensitivity reactions.
  • Discontinue the drug and consult with your physician if:
    • Your pain or nasal congestion last longer than 7 days
    • Fever lasts longer than 3 days or gets worse
    • You have redness or swelling
    • New symptoms appear
    • You experience dizziness, nervousness or sleeplessness
    • You develop severe skin reactions
  • Avoid drinking alcohol while taking acetaminophen/pheniramine/phenylephrine, it can damage your liver.
  • Avoid engaging in hazardous activities such as driving or operating heavy machinery while taking acetaminophen/pheniramine/phenylephrine, pheniramine can cause drowsiness.
  • Store acetaminophen/pheniramine/phenylephrine safely out of reach of children.
  • In case of overdose, seek immediate medical help or contact Poison Control.


Acetaminophen/pheniramine/phenylephrine is a combination medication used for the temporary relief of common cold and flu symptoms, including runny nose, itchy nose and throat, itchy and watery eyes, fever, headache, minor body aches, cough, sore throat, sneezing and nasal and sinus congestion. Common side effects of acetaminophen/pheniramine/phenylephrine include dizziness, fatigue, headache, insomnia, sedation, confusion, depression, euphoria, distress, irritability, restlessness, tremors, loss of appetite (anorexia), and others.

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 7/25/2023