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Histex

Generic name: triprolidine

Brand names: Histex PD Drops, Histex Syrup, M-Hist PD, PediaClear PD, Histex, Vanaclear PD, Vanahist PD

Used for Fever
Last updated November 2, 2026 0 views
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What is Histex?

Histex is an antihistamine that helps treat sneezing, runny nose, itchy nose and throat, and itchy or watery eyes caused by allergies like hay fever.

Histex may also be used for other reasons not mentioned in this medication guide.

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How should I take Histex?

Use exactly as directed on the label, or as prescribed by your doctor. Cold or cough medicine is only for short-term use until your symptoms clear up.

Always follow directions on the medicine label about giving cough or cold medicine to a child. Do not use the medicine only to make a child sleepy. Death can occur from the misuse of cough or cold medicines in very young children.

You must chew the chewable tablet before you swallow it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Call your doctor if your symptoms do not improve after 7 days, or if you have a fever, rash, or headaches.

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

Store at room temperature away from moisture and heat. Do not allow liquid medicine to freeze.

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Warnings

Follow all instructions on your medicine label and package. Inform each of your healthcare providers about all your medical conditions, allergies, and all medicines you are taking.

You should not use antihistamine medication to make a child sleepy.

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Before taking this medicine

You should not use Histex if you are allergic to it.

Ask a doctor or pharmacist if Histex is safe to use if you have:

  • a breathing disorder such as chronic bronchitis or emphysema;
  • glaucoma; or
  • an enlarged prostate and urination problems.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

This medicine may contain phenylalanine. Check the medication label if you have phenylketonuria (PKU).

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Histex 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.

Histex may cause serious side effects. Stop using Histex and call your doctor immediately if you have:

  • painful or difficult urination.

Common side effects of Histex may include:

  • dizziness, drowsiness;
  • blurred vision;
  • dry mouth, nose, or throat;
  • constipation;
  • increased urination; or
  • feeling nervous or restless (especially in children).

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.

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What happens if I miss a dose?

Since Histex is taken as needed, you might not follow a specific dosing schedule. If you miss a dose and it's nearly time for your next dose, just skip the missed dose. Do not take two doses at the same time.

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What happens if I overdose?

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

  • Avoid driving or doing anything dangerous until you understand how Histex will affect you. Your reactions could be affected.
  • Drinking alcohol can make some side effects of triprolidine worse.
  • Ask a doctor or pharmacist before using other cough or cold medicines that may have similar ingredients.
  • Avoid getting too hot or dehydrated while exercising or in hot weather. Histex can reduce sweating, and you may be at greater risk for heat stroke.

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What other drugs will affect Histex?

Do not use this medicine with other drugs that cause drowsiness or slow your breathing (such as opioid medicine, a muscle relaxer, or medicine for anxiety or seizures). Ask a doctor or pharmacist before using any other medication, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed in this medication guide.

This section was rewritten for readability and reviewed for meaning.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
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Content is provided for education and is not medical advice. See our medical disclaimer.