Theraflu vs Alka Seltzer

Theraflu vs Alka Seltzer – detailed comparison:

Theraflu Flu & Sore Throat

It is a combination of pheniramine, phenylephrine, and acetaminophen, which is used to relieve pain and reduce fever.

Phenylephrine is in a class of drugs called nasal decongestants that work by reducing swelling of the blood vessels in the nasal passages.

Acetaminophen is a medication that is used to treat pain and fever (high temperature). Its therapeutic properties are similar to salicylates. However, it lacks antiplatelet, anti-inflammatory, and gastric ulcerative properties.

Pheniramine is an antihistamine that reduces the natural chemical histamine in the body. It is an antihistamine with anticholinergic properties, which is used to treat allergic conditions, such as – urticaria or hay fever.


This product is used to treat flu and cold symptoms, like – sinus and nasal congestion, cough, sore throat, headaches, and body pain and aches.


The usual recommended dosage is 1 packet every 4 hours while symptoms persist.

Important note – do not take more than 5 packets in a 24-hour period.

Side Effects And Precautions

Common side effects may include:

  • ringing in the ears;
  • constipation;
  • problems with memory or concentration;
  • blurred vision;
  • feeling irritable or restless;
  • dizziness;
  • drowsiness;
  • dryness of the mouth, nose, and eyes;
  • stomach pain;
  • mild nausea.

Rare side effects may include:

  • little urinating;
  • unusual weakness;
  • shortness of breath;
  • shallow breathing;
  • chest pain;
  • severe dizziness or anxiety;
  • easy bruising or bleeding;
  • fast or uneven heart rate;
  • clay-colored stools;
  • tremor;
  • loss of appetite;
  • rapid pulse;
  • pain in the upper stomach;
  • confusion;
  • dark urine;
  • severe headaches;
  • yellowing of the skin or eyes;
  • seizure;
  • anxiety;
  • hallucinations.

Ask your healthcare provider whether it’s safe for you to take this medicine if you:

  • have chronic bronchitis;
  • have a liver disease;
  • have high blood pressure;
  • have an overactive thyroid;
  • have a blockage in your digestive tract;
  • drink more than 3 alcoholic beverages a day;
  • have a cough caused by smoking;
  • have an adrenal gland tumor (pheochromocytoma);
  • have asthma;
  • have emphysema (a progressive disease of the lungs that causes shortness of breath);
  • have a cough with mucus;
  • have heart disease;
  • suffer from chronic obstructive pulmonary disease;
  • have coronary artery disease.

Pregnancy & Breastfeeding

There are no clinical studies in women to determine the risk of using this drug during pregnancy or while breastfeeding.

Consult with your healthcare professional to weigh the potential risks and benefits before taking this drug.


Avoid drinking alcoholic beverages while taking this medication since alcohol may alter the way this drug works. Also, drinking alcohol may increase the risk of side effects.

Drug Interactions

It may negatively interact with other medicines, especially:

  • birth control pills;
  • methotrexate (a chemotherapy agent and immune system suppressant);
  • heart or blood pressure medications;
  • tuberculosis medicines;
  • antifungal drugs;
  • drugs for Parkinson’s disease (part of a group of conditions called motor system disorders);
  • arthritis or gout medications (including gold injections);
  • drugs to treat mental illness;
  • bronchodilators, such as – tiotropium or ipratropium;
  • potassium supplements;
  • bladder medicines, such as – fesoterodine, darifenacin, oxybutynin, or solifenacin;
  • cholesterol-lowering drugs, such as – Crestor, Lipitor, Atorvastatin, and Simvastatin;
  • HIV or AIDS drugs;
  • steroids, like – prednisone;
  • seizure medications;
  • antibiotics;
  • nonsteroidal anti-inflammatory drugs, such as – ibuprofen (Motrin), naproxen (Aleve), celecoxib (Celebrex), and indomethacin;
  • medications to treat excess stomach acid, stomach ulcer, irritable bowel syndrome, or motion sickness.

Alka-Seltzer Plus Cold Formula

It is the brand name of a combination of aspirin, chlorpheniramine, and phenylephrine.

Aspirin is in a group of medications called salicylates that work by reducing substances in the body that cause fever, pain, and inflammation.

Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. This is good during a cold since dilated blood vessels can cause nasal congestion.

Chlorpheniramine is an antihistamine agent which reduces the effects of the natural chemical histamine in the body. Histamine is an important neurotransmitter, but it can also produce symptoms of sneezing, watery eyes, itching, and a runny nose.


This medicine is typically used to treat runny or stuffy nose, fever, body aches, sneezing, itching, and watery eyes, caused by allergies, the flu, or the common cold.

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The usual recommended dosage is 2 tablets. You should take the tablets fully dissolved in 4 oz of water. The maximum recommended dosage is 8 tablets in a 24-hour period.

Side Effects and Precautions

Common side effects may include:

  • sleep problems (insomnia);
  • blurred vision;
  • feeling nervous or irritable;
  • drowsiness;
  • upset stomach;
  • dizziness;
  • constipation;
  • nausea;
  • heartburn;
  • dry mouth or throat.

Rare side effects may include:

  • worsening cold or flu symptoms;
  • coughing up vomit that looks like coffee grounds;
  • unusual weakness;
  • bloody or tarry stools;
  • shortness of breath;
  • uneven heart rate;
  • buzzing in your ears;
  • rapid pulse;
  • severe headaches;
  • chest pain;
  • easy bruising or bleeding;
  • little or no urinating;
  • seizure (convulsions);
  • severe nervousness;
  • hallucinations.

To be sure that this medication is good for you, tell your healthcare provider if you have:

  • glaucoma;
  • chronic bronchitis;
  • epilepsy or other seizure disorder;
  • a cough caused by smoking or emphysema;
  • overactive thyroid;
  • asthma or COPD;
  • if you take a potassium supplement;
  • if you are on a low-sodium diet;
  • a blockage in your stomach or intestines;
  • pheochromocytoma (an adrenal gland tumor);
  • stomach pain;
  • diabetes;
  • heartburn;
  • urination problems;
  • liver disease;
  • recent heart attack;
  • kidney disease;
  • coronary artery disease;
  • heart disease;
  • high blood pressure.

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Drinking alcoholic beverages can increase certain side effects (such as stomach bleeding) of this drug.

Drug Interactions

It may negatively interact with other medications, especially:

  • atorvastatin;
  • Advil (ibuprofen);
  • gabapentin;
  • amlodipine;
  • levothyroxine;
  • Benadryl (diphenhydramine);
  • Mucinex (guaifenesin);
  • Claritin-D (loratadine/pseudoephedrine);
  • omeprazole;
  • dyazide;
  • clonazepam;
  • tramadol;
  • hydrochlorothiazide;
  • Zyrtec (cetirizine);
  • lisinopril;
  • Tylenol (acetaminophen);
  • meloxicam;
  • simvastatin;
  • naproxen;
  • metformin.

Pregnancy & Breastfeeding

It is not known exactly whether this medication passes into breast milk or if it could negatively affect a nursing infant. Tell your doctor that you are breastfeeding a baby before using this medication.

Also, it may be harmful to an unborn baby’s heart. Do not use this drug if you are pregnant.

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Bottom Line – Theraflu vs Alka Seltzer

Theraflu Flu & Sore Throat (active ingredients – pheniramine, acetaminophen, and phenylephrine) is a combination medicine that is used to treat sinus congestion, headache, stuffy nose, runny nose, sneezing, watery eyes caused by the common cold or the flu.

Alka-Seltzer Plus Cold (active ingredients – aspirin, chlorpheniramine, and phenylephrine) is a combination medicine that is used to treat runny or stuffy nose, headache, fever, body aches, sneezing, itching, watery eyes, and sinus congestion caused by the common cold or the flu.

In conclusion, both products can be used to treat cold and flu symptoms, but both have plenty of side effects.

For example, according to New Zealand researchers, over-the-counter cold medicines that combine phenylephrine and acetaminophen can bring on side effects, including high blood pressure, tremors, and an irregular heartbeat.

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