Allegra-D 12 Hour Allergy and Congestion

Generic name: fexofenadine and pseudoephedrine [ FEX-oh-FEN-a-deen-and-SOO-doe-ee-FED-rin ]
Brand names: Allegra-D 12 Hour, Allegra-D 12 Hour Allergy and Congestion, Allegra-D 24 Hour Allergy and Congestion, Antihistamine and Nasal Decongestant, Fexofenadine HCl-Pseudoephedrine 12 Hour
Drug class: Upper respiratory combinations

Medically reviewed by Drugs.com on Aug 14, 2023. Written by Cerner Multum.

What is Allegra-D 12 Hour Allergy and Congestion?

Fexofenadine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

Allegra-D 12 Hour Allergy and Congestion is a combination medicine used to treat sneezing, runny or stuffy nose, itchy or watery eyes, hives, skin rash, itching, and other symptoms of allergies and the common cold.

Allegra-D 12 Hour Allergy and Congestion may also be used for purposes not listed in this medication guide.

Allegra-D 12 Hour Allergy and Congestion side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Allegra-D 12 Hour Allergy and Congestion may cause serious side effects. Stop using Allegra-D 12 Hour Allergy and Congestion and call your doctor at once if you have:

• pounding heartbeats or fluttering in your chest; or

• severe dizziness, anxiety, restless feeling, tremors, or nervousness.

Common side effects of Allegra-D 12 Hour Allergy and Congestion may include:

• mild dizziness;

• dry mouth, nose, or throat;

• nausea; or

• sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Do not use Allegra-D 12 Hour Allergy and Congestion if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

Before taking this medicine

Do not use Allegra-D 12 Hour Allergy and Congestion if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Ask a doctor or pharmacist if it is safe for you to take this medication if you have:

• kidney disease;

• glaucoma;

• heart disease or high blood pressure;

• diabetes;

• thyroid disorder; or

• bladder obstruction or other urination problems.

It is not known whether Allegra-D 12 Hour Allergy and Congestion will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

Pseudoephedrine can pass into breast milk and may cause side effects in the nursing baby. Ask a doctor before using this medicine if you are breast-feeding.

Do not give this medicine to a child without medical advice.

How should I take Allegra-D 12 Hour Allergy and Congestion?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended. Cold or allergy medicine is usually taken only for a short time until your symptoms clear up.

Do not give this medication to a child younger than 2 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Take Allegra-D 12 Hour Allergy and Congestion on an empty stomach, at least 1 hour before or 2 hours after a meal.

Take Allegra-D 12 Hour Allergy and Congestion only with water. Avoid fruit juice; especially orange, apple, or grapefruit juice. Fruit juice can make it harder for your body to absorb fexofenadine.

Call your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache, cough, or skin rash.

If you need surgery or medical tests, tell the surgeon or doctor ahead of time if you have taken a cold or allergy medicine within the past few days.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Since cold or allergy medicine is taken as needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking Allegra-D 12 Hour Allergy and Congestion?

Avoid using antacids within 15 minutes before or after taking Allegra-D 12 Hour Allergy and Congestion. Antacids can make it harder for your body to absorb this medication.

Ask a doctor or pharmacist before using any other cold or allergy medicine. Many combination medicines contain pseudoephedrine. Taking certain products together can cause you to get too much of Allegra-D 12 Hour Allergy and Congestion.

Drinking alcohol can increase certain side effects of this medication.

What other drugs will affect Allegra-D 12 Hour Allergy and Congestion?

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking Allegra-D 12 Hour Allergy and Congestion with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with fexofenadine and pseudoephedrine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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

Medical Disclaimer

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